COMMISSIONS AND OF THE I A U
INFORMATION BULLETIN ON VARIABLE STARS
Nos
Octob er May
EDITORS L SZABADOS and K OLAH
TECHNICAL EDITOR A HOLL
TYPESETTING K ORI
KONKOLY OBSERVATORY
H BUDAPEST
P O Box HUNGARY
IBVS ogyalla konkoly hu
URL http www konkoly hu IBVS IBVS html
HU ISSN 2
CONTENTS
1994
No page
E F GUINAN J J MARSHALL F P MALONEY A New Apsidal
Motion Determination For DI Herculis :::::::::::::::::::::::::::::::::::::
D TERRELL D H KAISER D B WILLIAMS A Photometric
Campaign on OW Geminorum ::::::::::::::::::::::::::::::::::::::::::::
B GUROL Photo electric Photometry of OO Aql ::::::::::::::::::::::::
LIU QUINGYAO GU SHENGHONG YANG YULAN WANG BI New
Photo electric Light Curves of BL Eridani ::::::::::::::::::::::::::::::::::
S Yu MELNIKOV V S SHEVCHENKO K N GRANKIN Eclipsing
Binary V Cyg S Former Ins a Type Variable ::::::::::::::::::::
J A BELMONTE E MICHEL M ALVAREZ S Y JIANG Is
Praesep e KW Actually a Delta Scuti Star :::::::::::::::::::::::::::::
V L TOTH Ch M WALMSLEY Water Masers in L ::::::::::::::
R L HAWKINS K F DOWNEY Times of Minimum Light for Four
Eclipsing of Four Binary Systems ::::::::::::::::::::::::::::::::::::::::::
B GUROL S SELAN Photo electric Photometry of the Short Period
Eclipsing Binary HW Virginis ::::::::::::::::::::::::::::::::::::::::::::::
M P SCHEIBLE E F GUINAN The Sp otted Young Sun HD
EK Dra ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::
M BOS Photo electric Observations of AB Doradus :::::::::::::::::::::
YULIAN GUO A New V R Cyclic Change of H in Tau ::::::::::::::
YULIAN GUO A Detection of Moving Bumps in the Emission Pro les of
the Be Star FX Lib ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::
J R PERCY W AU APT Observations of Small Amplitude Red
Variables ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::
J C THOMAS I PACHOULAKIS V and UV Photometry of HD
J MANEK CF Cas NSV :::::::::::::::::::::::::::::::::::::::
M ALUIGI G GALLI A GASPANI Photo electric Observations of the
Close Eclipsing Binary VW Cephei :::::::::::::::::::::::::::::::::::::::::
V MAKAROV U BASTIAN E HOEG V GROSSMANN
A WICENEC New Bright Medium and High Amplitude Variables
Discovered by the Tycho Instrument of the Hipparcos Satellite ::::::::::::::
D H KAISER Five New DHK Variables ::::::::::::::::::::::::::::::::
C STERKEN J MANFROID A Flare Event on HR :::::::::::::::
W WENZEL The Long Term Photometric Behaviour of the Cataclysmic
Binary HX Pegasi ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::
D P KJURKCHIEVA D V MARCHEV Eclipse Curves of UX UMa in
::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::::
B E SCHAEFER D HOFFLEIT KY Ara is Misidenti ed :::::::::::::
P NORTH M BURNET Geneva Photometry of the Eclipsing Binary
TV Nor ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::
S V ANTIPIN Ten New Variable Stars in Hercules and Corona Borealis 3
No page
O DEMIRCAN M TANRIVER A DEVLEN A BULUT
A SAVRANLAR Y YUKSEL A A S CILAR Z ASLAN H AK
A GOK CE E CINAR G SEN G TA S E A CIKGOZ C IBANOGLU
H DUNDAR H CALI SKAN H VARLI H OZDEMIR Y ALEMDAR
B BEKTA SLI Z MUYESSEROGLU B ALBAYRAK A ISKENDER
N CUBUKCU O CAKIRLI R T YILDIRIM F GOKSEN S O SELAM
K YUCE Y KAYA K ULU C M DAGCI Y ERDAL N KOKER
Photo electric Observations and Minima Times of Four W UMa Systems
LS Del SW Lac V Oph and AQ Psc ::::::::::::::::::::::::::::::::::
P A HECKERT BVRI Photometry of CG Cygni ::::::::::::::::::
L T MARKOVA G V ZHUKOV B and V Photo electric Observations
of the Contact Binary XY Leo :::::::::::::::::::::::::::::::::::::::::::::
V P GORANSKIJ The Identi cation of Variable Stars Discovered with
the Hubble Space Telescope in the Globular Cluster Messier ::::::::::::::
N A GORYNYA N N SAMUS A S RASTORGOUEV Sp ectroscopic
Binarity of the Cepheid BY Cas :::::::::::::::::::::::::::::::::::::::::::
F AGERER WW Cephei Elements Rediscovered and Improved ::::::::
F AGERER W KLEIKAMP W MOSCHNER V Lyrae New
Ephemeris and Lightcurve :::::::::::::::::::::::::::::::::::::::::::::::::
F AGERER Photometric Observation of V Cygni ::::::::::::::::::
F AGERER T BERTHOLD VW Canum Venaticorum New Ephemeris
and Lightcurve ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::
K T JOHANSEN B NORDSTROM A Pre Main Sequence Companion
to AR Aurigae ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::
T KATO AK Cancri a New Large Amplitude SU UMa Type Dwarf
Nova ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::::
S V ANTIPIN N N KIREEVA N N SAMUS Positions of Variable
Stars in Plaut s Field ::::::::::::::::::::::::::::::::::::::::::::::::::: :
A P ODELL Timings of Selected Variable Stars ::::::::::::::::::::::::
E BUDDING G HUDSON R HUDSON UBV Observations of AB Dor
::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::::
E V KAZAROVETS N N SAMUS The nd Name List of Variable
Stars ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::
L N BERDNIKOV O V VOZIAKOVA M A IBRAGIMOV BVR
Observations of the Double Mo de Cepheids AS Cas V Sct and BQ Ser :
L N BERDNIKOV O V VOZIAKOVA M A IBRAGIMOV UBVR
Observations of the Double Mo de Cepheids CO Aur TU Cas and EW Sct ::
F AGERER P FRANK Photometric Observation of NS Mono cerotis :::
E LAPASSET N GOMEZ AW Virginis Photo electric Times of Minimum
and Improved Period ::::::::::::::::::::::::::::::::::::::::::::::::::: :::
L N BERDNIKOV O V VOZIAKOVA Photo electric UBVR
Observations of the Peculiar Cepheid V Lyr ::::::::::::::::::::::::::::
D Yu TSVETKOV N N PAVLYUK Observations of SN ad ::::::
P NORTH C RICHARD HD An Eclipsing Magnetic Ap Star
at Last ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::: 4
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J D FERNIE N R EVANS B BEATTIE S SEAGER A Database of
Galactic Classical Cepheids ::::::::::::::::::::::::::::::::::::::::::::::::::
CHA GUANGWEI LI YONGSHENG XU JUN Short Time Scale
Variation of Aur H Blue Wing Emission ::::::::::::::::::::::::::::::::
Z BALOG J VINKO Is TX Delphini a Population I Classical
Cepheid ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::
E PAUNZEN U HEITER W W WEISS Detection of Variability in
HD ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::
T KATO Observations of Sup erhumps in V Cyg during the
Sup eroutburst ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::
M ALUIGI G GALLI A GASPANI Photo electric Observations of the
Eclipsing Variable DO Cas ::::::::::::::::::::::::::::::::::::::::::::::::
L N BERDNIKOV O V VOZIAKOVA Photo electric UBVR
Observations of the Peculiar Cepheid RU Cam :::::::::::::::::::::::::::::
D NOGAMI T KATO S MASUDA R HIRATA Discovery of the
Second PG Typ e Dwarf Nova V Ori ::::::::::::::::::::::::
S RUCINSKI R F GARRISON B DUFFEE U Filter Photometry of
AB Doradus ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::
A SKOPAL Photometric Observations of Eclipses in the Symbiotic Triple
System CH Cygni ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::
A V BERDYUGIN T M RACHKOVSKAJA S I ROSTOPCHIN
A E TARASOV The Discovery of H Emission in V Cas :::::::::::::
R WASATONIC A Possible Variable Star Reclassi cation for TX Piscium
V N OBRIDKO Yu R RIVIN Solar Magnetic Field Mo dulation of the
Neutrino Flux ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::
J J MARSHALL E F GUINAN G P McCOOK Possible Low
Amplitude Light Variations of DI Her :::::::::::::::::::::::::::::::::::::
E S PARSAMIAN On the Age of Flare Star FS and the Cluster
of Persei ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::
D NOGAMI T KATO S MASUDA R HIRATA Observations of
a Newly Discovered SU UMa Type Star HV Aurigae :::::::::::::::::::::::
D HOFFLEIT More Clari cation Needed for NSV and VY Lyrae
M J SARNA W PYCH R C SMITH New Period Determination for
EY Cyg ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::
L L KISS K SZATMARY Has the Delta Scuti Star BE Lyn a
Companion ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::
R G SAMEC B CARRIGAN E E PADGEN Precision B V Light
Curves of EK Comae Berenices ::::::::::::::::::::::::::::::::::::::::::::
D H KAISER M E BALDWIN J GUNN D TERRELL C STEPHAN
B HAKES Period Correction for the New Eclipsing Binary DHK :::::::
L A MILONE Faint Companions to UX Antliae ::::::::::::::::::::::::
E RODRIGUEZ F M ZERBI A Long Period Early F Type Variable
HR ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::
K BARLAI B SZEIDL Onset of Pulsation of V in M ::::::::::::: 5
No page
H ROVITHIS LIVANIOU P ROVITHIS G OPRESCU
A DUMITRESCU New Minima Times and Period Behaviour for the
Eclipsing Variables RT Andromedae i Bo otis and GO Cygni :::::::::::::
R HUDEC Optical Monitoring of Two X Ray Transient Sources ::::::::
R W HANUSCHIK S STEFL W HUMMEL M VRANCKEN
Observations of a V R Transition in the Be Star Oph ::::::::::::::::::
A SCHNELL H M MAITZEN Photometric Examination of
CP Peculiarity for HD HR HR and HR ::::::::::::::
K KRISCIUNAS E F GUINAN G P McCOOK R F GRIFFIN
R A CROWE M ROBERTS K D LUEDEKE P POBOCIK Photometric
Variability of the Ellipsoidal Star and Sp ectroscopic Binary Camelopardalis
J D GRAY R G SAMEC B J CARRIGAN Complete CCD U B V
R I Light Curves of the Short Period Eclipsing Binary V Lyrae ::::::::
R HAEFNER CCD Photometry of Six Faint Cataclysmic Variables :::::
E WUNDER The First Period Change Discovered in the Bright Algol
System UV Leonis ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::
M JASCHEK C JASCHEK P KEENAN N GINESTET
J M CARQUILLAT HD An UU Her Sp ectrum Variable :::::::::::
L L KISS J GAL G KASZAS New Times of Minima of
Eclipsing Binaries VW Cep U Cep and RZ Cas :::::::::::::::::::::::::::
W WENZEL G A RICHTER R LUTHARDT R SCHWARTZ The
Orbital Period of the ROSAT Cataclysmic Variable S Comae Berenices
W WENZEL A New Semiregular Variable S in Corona Borealis ::::::
Erratum ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::
E STEINBRING D P HUBE B E MARTIN The Ellipsoidal
Variability of HR ::::::::::::::::::::::::::::::::::::::::::::::::::: ::
D M POPPER Narrowing the Main Sequence Mass Gap :::::::::::::::
R G SAMEC R J McDERMITH B J CARRIGAN UBV Light
Curves of the Near Contact Binary AK Canis Minoris ::::::::::::::::::::::
W R BENBOW R L MUTEL Eclipse Observations of EQ Tau :::::::
G HANDLER HD Is Variable but It Is Not a Delta Scuti Star :::
R K ZAMANOV V I ZAMANOVA X Persei :::::::::::::::::::::::::
F ZEINALI M T EDALATI M T MIRTORABI Photo electric
Observations of the Eclipsing Variable ER Vulpeculae ::::::::::::::::::::::
E PAUNZEN U HEITER W WEISS Con rmation of Variability in
the Bo otis Stars HD and HD ::::::::::::::::::::::::::::::
M ROBB The Active Star RE ::::::::::::::::::::::::::::::::
T KATO D NOGAMI S MASUDA R HIRATA HS Virginis a Dwarf
Nova with Day Outburst Cycle Length ::::::::::::::::::::::::::::::::::
G H SANDBERG LACY C IBANOGLU Z TUNCA S EVREN C
AKAN V KESKIN M ZAKIROV G ARZUMANYANTS
R ISHANKULOV V KHARCHENKO Times of Minima of Eight Eclipsing
Binaries ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::
K KRISCIUNAS G HANDLER A List of Variable Stars Similar to
Dor ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::::
D B WILLIAMS Periods and Types for Six Red Variables :::::::::::::: 6
No page
T S METCALFE BH Cas Is An Eclipsing Binary ::::::::::::::::::::::
R H DIETHELM L MOSER NSV Bo o BV RRab Variable
N A GORYNYA N N SAMUS L N BERDNIKOV
A S RASTORGOUEV M E SACHKOV Orbital Parameters of Six
Sp ectroscopic Binary Cepheids :::::::::::::::::::::::::::::::::::::::::::::
L N BERDNIKOV O V VOZIAKOVA D G TURNER Photo electric
Observations of the T Tau Type Variable BZ Sgr :::::::::::::::::::::::::: 7
AUTHOR INDEX
A cikg oz E Du ee B
Agerer F Dumitrescu A
D undar H
Ak H Edalati M T
Akan C Erdal Y
Albayrak B Evans N R
Alemdar V Evren S
Aluigi M Fernie J D
Alvarez M Frank P
Antipin S V G al J
Arzumanyants G Galli G
A scilar A Garrison R F
Aslan Z Gaspani A
Au W Ginestet N
Baldwin M E G omez M
Balog Z Goranskij V P
Barlai K Gorynya N A
Bastian M G oksen F
Beattie B G ork ce A
Bekta sli B Grankin K N
Belmonte J A Gray J D
Benbow W R Gri n R F
Berdnikov L N Grossmann V
Gu Shenghong
Berdyugin A V Guinan E F
Berthold T Gunn J
Bos M Guo Yulian
Budding E G urol B
Bulut A Haefner R
Burnet M Hakes B
Cali skan H Handler G
Calirli O Hanuschik R V
Carquillat J M Hawkins R L
Carrigan B Heckert P A
Cha Guangwei Heiter H
Cinar E Hirata R
Crowe R A Ho eit D
Cubukcu N Ho eg E
Da gci M Hub e D P
Demircan O Hudec R
Devlen A Hudson G
Diethelm R Hudson R
Downey F Hummel W 8
Ibano glu C Moser L
Ibragimov M A Mutel R L
Ishankulov Z M uyessero glu Z
Iskender A Nogami D
Jaschek C Nordstr om B
Jaschek M North P
Jiang S Y Obridko V N
Johansen K T Odell A P
Kaiser D H Oprescu G
Kasz as G Ozdemir H
Kato T Pachoulakis I
Kaya Y Padgen E E
Kazarovets E V Parsamian E S
Keenan P Paunzen K
Keskin V Pavlyuk D Yu
Kharchenko V Percy J R
Kiss L L Pobo cik P
Kireeva N N Popper D M
Kjurkchieva D P Pych W
Kleikamp W Rachkovskaja T M
K oker N Rastorgouev A S
Krisciunas K Richard C
Lacy C H S Richter G A
Lapasset E Rivin Yu R
Li Yongsheng Robb M
Liu Quingyao Rob erts M
Luedeke K D Ro driguez E
Luthardt R Rostop chin S I
Maitzen H M Rovithis P
Makarov V Rovithis Livaniou H
Maloney F P Rucinski S
M anek J Sachkov M E
Manfroid J Samec R G
Marchev D V Samus N N
Markova L T Sarna M J
Marshall J J Savranlar A
Martin B E Schaefer B A
Masuda S Scheible M D
McCo ok G P Schnell A
McDermith R J Schwartz R
Melnikov S Yu Seager S
Metcalfe T S Selan S
Michel E Sen G
Milone L A Shevchenko V S
Mirtorabi M T Skopal A
Moschner W Smith R C 9
Ste S
Steinbring E
Stephan Ch
Sterken C
Szatm ary K
Szeidl B
Tanriver M
Tarasov A E
Ta s G
Terrell D
Thomas J C
T oth V L
Tsvetkov D Yu
Tunca Z
Turner D G
Ulu c K
Varli H
Vink o J
Voziakova O V
Vrancken M
Walmsley Ch M
Wang Bi
Wasatonic R
Wenzel W
Weiss W
Wicenec A
Williams D B
Wunder E
Xu Jun
Yang Yulan
Yildirim R T
Y uce K
Y uksel Y
Zakirov M
Zamanov R K
Zamanova V I
Zhukov G V
Zeinali F
Zerbi T M 10
INDEX OF VARIABLES
Name No Name No
RT And V
XZ
U Cep
BX
VW
UX Ant WW Cep
EK
FF Aql
OO EK Com
KY Ara V CrA
AR Aur W Crv
CO
VZ Cyg
HP
CG
HV
CH
Epsilon
EY
GO
TY Bo o MW
BY HR V
CF HR V S
CV V
i V
V
RU Cam
HR TX Del
LS
AK Cnc
AB Dor
AK CMi
Gamma
VW CVn
EK Dra HD
BP
CV HR
RZ Cas
BL Eri
XX
Nu
TU
AS OW Gem
BH
CF Gru
BY
DI Her
CE
CF NSV
SW Lac
DO
V
IT
XY Leo
PV
UV
QX
DU
V
V HD
FX Lib 11
Name No Name No
V
BE Lyn
V
VY Lyr
V
V
V
V
V
V
V
FS Mon
V
NS Mon
V V Sgr
V V Sgr
TV Nor
V
V Oph
V V Sgr
V V Sgr
V V Sgr V Sgr
FT Ori
V
GG
V
V Sgr
HX Peg
Sigma Sco
LM
EW Sct
X Per
V
V
BQ Ser
TX Psc
TT Sex
UV
AQ
AP Tau
EQ
Pup B
V
S Sge
Zeta
BZ Sgr
UX UMa
V
ZZ
V V Sgr
AW Vir
V V Sgr V Sgr
BH
V V Sgr V Sgr
HS PG
V NSV
HW
V NSV
V V Sgr BW Vul
V V Sgr ER
V V Sgr
BV NSV
V V Sgr
DHK GSC
V
DHK SAO
V
DHK GSC
V
DHK SAO
V
DHK SAO
V
V V Sgr
GSC
V
GSC NSV
V
GSC 12
Name No Name No
GSC HD
GSC HD
GSC DHK HD
GSC HD
GSC DHK HD
GSC HD CP
GSC HD
GSC HD
GSC HD
GSC HD
GSC HD
GSC
HR Cam
GSC
HR
GSC
HR
GSC
HR
GSC
HR
GSC
HR
GSC NSV
HR
GSC
HR
GSC
HR CV Dra
GSC NSV
HR
GSC
HR
GSC
HR BY Bo o
GSC
HR CF Bo o
GSC
HR
GSC NSV
KW
GSC
GSC
L
GSC
NSV BV
GSC NSV
NSV GSC
GSC
NSV GSC
GSC
NSV GSC
GSC
NSV GSC
GSC NSV
NSV HR
GSC
NSV GSC
GSC
NSV GSC
GSC
NSV
GSC
NSV
GSC
NSV
GSC
NSV V Sgr
Hawkins V
NSV V Sgr
NSV
HD V Cas
NSV
HD
NSV
HD EK Dra
NSV CF Cas
HD A 13
Name No Name No
PG HS Vir GSC
PG GSC
PG GSC
GSC NSV
RE BD
GSC
S V Cyg
GSC
S
GSC NSV
S
GSC
GSC
SAO DHK
GSC
SAO DHK
GSC
SAO DHK
GSC NSV
SN ad
GSC
GSC
X ray sources
GSC
GRO
GSC NSV
GROJ GRS
GSC
GRS GROJ
GSC
New variables
GSC
GSC NSV
E
GSC
in Alpha Per FS
GSC
nd Name List
GSC
Cam HR
GSC
in Her and CrB
GSC
DHK GSC
GSC
DHK SAO
Hawkins V
DHK GSC
DHK SAO
HD
DHK SAO
HD A
HD
GSC
HD
GSC NSV
HD
GSC
HD
GSC
HD
GSC
HD CP
GSC
HD
GSC
HD
GSC
HD
GSC
HD
GSC
HD
GSC
GSC
HR Cam
GSC
HR
GSC
HR
GSC
HR 14
Name No
HR
HR
HR
HR
HR
HR
HR
L
PG
PG
S
S
Variables in clusters
in Alpha Per FS
in M V
in M
in NGC 15
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
A NEW APSIDAL MOTION DETERMINATION FOR DI HERCULIS
DI Herculis HD is an th magnitude eclipsing binary consisting of two main
sequence B stars B V and B V moving in a highly eccentric orbit e with a
p erio d of approximately days Rudkj bing rst called attention to this system
as a p ossible test of general relativity since the relativistic contribution to the total apsidal
motion is exp ected to b e greater than that arising from classical Newtonian e ects For
DI Her the classical contribution to the apsidal motion rate which arises from tidal and
rotational deformation of the stars is exp ected to b e yr yr
cl
while the theoretically exp ected general relativistic contribution is yr
g r
yr yielding a combined predicted value of yr yr
cl+g r
Guinan and Maloney The rate of the observered apsidal motion of DI Her is well
determined from measurements of the times of primary and secondary eclipse However
in all studies done so far for DI Her the results indicate an apsidal advance signi cantly
smaller than predicted from theory For example Guinan and Maloney found a
value of yr yr and Reisenberger and Guinan found
obs
yr yr The observations used in these studies span a p erio d
obs
of ab out years and indicate an apsidal motion rate times smaller than exp ected
from theory This discrepancy b etween the observed and theoretical apsidal motions for
this star is very puzzling One of the p ossible explanations for the smaller than exp ected
observed apsidal motion in DI Her is the presence of a third b o dy which would p erturb
the orbit of the close eclipsing pair see Guinan and Maloney Reisenberger and
Guinan and Khaliullin Kho dykin and Zakharov
We have continued to observe DI Her extending the observational baseline to provide a
more accurate determination of the rate of apsidal motion and also to search for evidence
of small p erio d oscillations due to the presence of a p ossible third b o dy Here we rep ort on
three new times of minimum light obtained by us using a m Automatic Photo electric
Telescope APT these data are combined with all the previous photo electric timings to
search for evidence of a third b o dy and to re ne the determination of the apsidal motion
Photo electric photometry was carried out during the spring of and resulting
in three new timings of minimum light a secondary eclipse on June UT and
two primary eclipses on June UT and May UT Observations were
made using the Fairborn Villanova m APT on Mt Hopkins Arizona observations
were taken in Johnson U B and V lters Di erential magnitudes were computed in
the sense variable minus comparison V C where HD V B served as
the comparison star while HD V A served as the check star Extinc
tion corrections were applied using atmospheric extinction co e cients determined from
observations of the comparison star and lo cal standard times were converted into helio
centric Julian days HJD The data were reduced using software developed at Villanova
University by G P McCo ok The details of the reduction pro cedure have b een describ ed
Figure A plot of the di erential V magnitudes obtained
during primary eclipse of DI Her on May UT
Figure The plots of the O C values versus Julian Date for the
photo electric times of primary and secondary eclipses The O C s
were computedfrom equations and and show no evidence of
signi cant systematic variations exp ected to arise from a third b o dy
Figure Plot of the displacement of the secondary minimum from a
half p erio d p oint of DI Her in days D t t P
1 2
versus Julaian Date number
elsewhere by Guinan et al The di erential V magnitudes of the primary eclipse
observed on May UT are shown in Figure
The times of minimum light were initially determined by a computerized version of the
familiar tracing pap er metho d The reduced data are plotted on the screen as observed
and then plotted again with the time axis reversed The second curve is then p ositioned
so that the two curves app ear sup erimp osed and the time of minimum then app ears at
the same p oint on b oth curves We then formally applied a second order parab olic and
fourth order least squares t on the data for the eclipses The agreements b etween the
times given by the computerized tracing pap er metho d and the least squares ts are
very go o d The b est ts were obtained using the fourth order calculations Because of the
large number of data p oints ab out p er night p er lter and go o d distribution through
the minimum we have obtained very precise determinations of the eclipse timings The
nal times of minimum light were obtained by determining the time of minimum indep en
dently in the B and V lters p erforming the fourth order least squares t and averaging
the two results We did not use the U band observations in these determinations b ecause
they were noisier than the B and V band data Our three new times of minima and their
corresp onding O C values determined using the ephemeris given by Reisenberger and
Guinan are
T min I I HJD O C day
T min I HJD O C day
T min I HJD O C day
It should b e noted that the higher observational error indicated for the secondary mini
mum results in part b ecause the lowest p ortion of the minimum was not covered As a
result of this this timing should b e given a somewhat lower weight
These eclipse timings and those given by Kho dykin and Volkov Caton and
Burns and Lacy and Fox were combined with only the more accurate pho
to electric timings that have b een tabulated by Guinan and Maloney and Reisen
b erger and Guinan Linear least squares ts were made indep endently to the
primary and secondary eclipse data and the following light elements were determined
T min I HJD
T min I I HJD
In Figure we have plotted the O C s found from these ts for b oth primary and
secondary eclipses This gure includes data from to As shown in these plots
there is no evidence of any systematic or p erio dic variations in the O C s to a level of
ab out days that would suggest the light time e ect from a putative third b o dy
These data do not rule out the p ossibility of a companion but certainly do not lend any
supp ort to this hypothesis It should also b e noted that there is no signi cant change
to within mag in the observed eclipse depth compared to previous photo electric
photometry This indicates that the orbital inclination has b een constant to within ab out
and therefore there is no observed evidence for p erturbations from a third b o dy
Following the pro cedure describ ed by Guinan and Maloney an apsidal motion
rate of yr yr was determined from the change with time of
obs
the displacement of the secondary minimum from the half p erio d p oint Figure shows
the change in the displacement of the secondary minimum D t t P with time
1 2
where t and t are the times of primary and secondary eclipse resp ectively The apsidal
1 2
motion rate found here is essentially the same rate as found previously by Reisenberger
and Guinan and in close agreement to the values given by Guinan and Maloney
and Kho dyin and Volkov
We plan to continue our study of DI Her and will attempt to obtain more photo electric
timings of primary and secondary eclipses during the next several years to further re ne
the observed rate of apsidal motion and to continue the search for evidence of a third
b o dy
This work has b een supp orted by NSF grants AST and AST which
we gratefully acknowledge
Edward F GUINAN
James J MARSHALL
Frank P MALONEY
Department of Astronomy
and Astrophysics
Villanova University
Villanova PA
USA
References
Caton D B and Burns W C I B V S No
Guinan E F Na ja S Zamani No or F Boyd P T and Carroll S M I B V S
No
Guinan E F and Maloney F P Astrophys J
Khaliullin Kh F Kho dykin S A and Zakharov A I Astrophys J
Kho dykin S A and Volkov I M I B V S No
Lacy C H S and Fox G W I B V S No
Reisenberger M P and Guinan E F Astron J
Rudkj bing M Ann Astrophys
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
A PHOTOMETRIC CAMPAIGN ON OW GEMINORUM
The eclipsing nature of the th magnitude variable star OW Gem BD
HDE was discovered by Kaiser Kaiser et al who also determined the
p erio d of days from a study of Harvard patrol plates Kaiser The re
markable primary eclipse is more than magnitudes deep and two weeks in duration
m
Williams found the secondary eclipse : deep at phase indicating that the
orbit is highly eccentric
Gri n and Duquennoy published a rst general investigation of the system
based on radial velocity measures over a full orbital cycle and matches of mo del light
curves to the available eclipse photometry They found that the system contains two
luminous giants the primary sp ectral type b eing F Ib I I and the secondary ab out G I Ib
Comp onent masses are close to M and M
The orbital eccentricity is in such an orientation ! that the stars have
twice the separation at secondary eclipse as at primary eclipse As a result the primary
eclipse lasts days the secondary days
Eclipses and a double lined sp ectrum make OW Gem a favorable sub ject for compre
hensive investigation Radial velocity observations are continuing so b etter understanding
of the system is now constrained by the available photometry mostly visual and photo
graphic estimates for the primary eclipse and sparse photo electric observations in only
one color for the secondary eclipse
Since the primary and secondary minima the eclipses have o ccurred near
solar conjunction During however b oth eclipses will b e favorably placed for obser
vation the primary eclipse o ccurring from February and the secondary eclipse from
November December
Observations from widely spaced longitudes will help to ll in the eclipse light curves
and avoid weather gaps during the northern hemisphere s winter months We therefore
invite suitably equipp ed observers to participate in an international photometric campaign
on OW Gem during with the lead author serving as co ordinator
m
Participating observers should b e able to achieve : precision down to in V and
in B during the primary eclipse The secondary minimum V B is brighter
but the demand for precision remains high in order to de ne the shallow eclipse Multiple
passband observations are very desirable and infrared observations would show a deep er
secondary eclipse than visible ones Because observations from a variety of instruments
and detectors must b e combined observers are asked to take particular care in determining
color transformation co e cients and standardizing the observed di erential magnitudes
All observers should use the same comparison and check stars The designated com
parison star is SAO BD HD V marked as star on the
chart in IBVS No Kaiser et al The check star is GSC V star
marked on the chart These stars are similar in color to the variable and are lo cated
Figure Finding chart for OW Geminorum
within arcminutes which will assist observers using CCD detectors with limited elds
Figure shows a nding chart for the system
All interested observers are urged to register with the lead author We intend to
distribute a circular with nal information prior to the rst event and again following
each of the two eclipses
Daniel H KAISER
Dirk TERRELL
Crescent Mo on Observatory
Department of Physics and Astronomy
Washington St Columbus
University of Calgary
IN USA
Calgary Alb erta T N N
E Mail d kaiser genie geis com
E Mail terrell algol iras ucalgary ca
David B WILLIAMS
A Racquetball Way
Indianap olis IN USA
References
Gri n R F and Duquennoy A The Observatory
Kaiser D H Inf Bul l Var Stars No
Kaiser D H Williams D B and Baldwin M E Inf Bul l Var Stars No
Williams D B Journ AAVSO
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
PHOTOELECTRIC PHOTOMETRY OF OO Aql
OO Aquilae BD HD SAO is a ninth magnitude binary with
a W Ursae Maioris type light curve and relatively deep minima Photo electric light curves
have b een published by Binnendjik and Lafta and Grainger Binnendijk
found over several seasons that the shap e of the light curves varied with time Demircan
and G ud ur have published B and V observations and have also gathered a large
number of times minimum light as a part of a p erio d study In addition a number of
other observers have published o ccasional times of minimum light
A sp ectral type of G has b een assigned to the system by Roman and K by
Hill et al based up on classi cation sp ectra
Photo electric UBV observations of the W UMa type eclipsing binary OO Aql were
carried out in the years and at Ankara University Observatory During
a program of photo electric observations of eclipsing binaries the system was observed in
in two colours B and V and in and in three colours U B and V
The observations were made with a cm Maksutov telescop e equipp ed with an SSP A
photometer head which is used with an Hamamatsu R photomultiplier tub e Before
September the observations were made by using an EMI QB photomultiplier
attached to the Maksutov telescop e The lters used are in close accordance with the
standard UBV bands
The same comparison star BD was chosen as by Demircan and G ud ur
and Lafta and Grainger for nearness in p osition and brightness to OO Aql All
di erential observations were reduced outside the atmosphere using the extinction co
e cients calculated in the usual way and helio centric correction was made for all the
observations The phases were calculated with the new light elements as
d
T E
The observations are shown in Figures and for the years and
resp ectively together with the B V and U B colour curves observations in
Figure were made with b oth photomultipliers cited ab ove
Total of six primary and six secondary times of minima were calculated using Kwee
and van Woerden s metho d and listed in Table with their mean errors The
columns in Table are minima type helio centric Julian Date mean error I which found
by Kwee and van Woerden s metho d and lters used resp ectively The last two
columns are the averaged minima times mean and mean errors I I calculated using the
function given as follows
P
t
i
i
i
t
P
min mean
i
i
and Mean err I I
P
mean
i i
Figure
Figure Figure
Table I
Min HJD min Mean Filters HJD min Mean
Type err mean err
I I I
I B
I V
I B
II B
II V
II B
II V
II B
II U
II B
II V
I U
I B
I V
I U
I B
I V
II B
II V
II U
I U
I V
I B
I V
I U
I B
II U
II V
II B
Birol GUROL
Ankara University Observatory
Tando gan Ankara
T urkiye
References
Binnendijk L A J
Demircan O G ud ur N in Photometric and Sp ectroscopic Binary Systems ed
E B Carling and Z Kopal D Reidel Publ p
Hill G Hilditch R W Younger F and Fischer W A Mem RAS
Kwee K K van Woerden H Bul l Astron Neth
Lafta S J Grainger J F Ap Space Sci
Roman N G Ap J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
NEW PHOTOELECTRIC LIGHT CURVES OF BL ERIDANI
Photo electric observations of BL Eri BD were carried out in December
with the m telescop e at Yunnan Observatory in China Di erential measurements
made on two nights in B and V resulted in individual observations in each bandpass
The two stars BD and BD were chosen as the comparison star and the
check star resp ectively The observational accuracy throughout the observing p erio d as
m
derived from the magnitude di erences b etween the two comparison stars is : V
m
and : B
The times of minimum light for BL Eri shown in Table I were determined by a least
squares analysis The O C values in Table I were computed from the following ephemeris
d
Min I Hel J D : E
p e
which was derived by a least squares analysis utilizing all the photo electric times of
minimum light
Figure Light curves of BL Eri in V The op en circles show the
present observations and the lled circles indicate Yamasaki et al s
observations in and
Figure As Figure but in B
Table I Times of minimum light for BL Eri
Hel J D Min Ep o ch O C
II
I
The light variations of BL Eri relative to BD magnitudes di erences in the
sense variable comparison are shown in Figure V and Figure B as op en
circles the present observations and lled circles Yamasaki et al s observations in
and Yamasaki et al The light curves indicate that signi cant stellar activity
probably o ccurs in this binary
LIU QUINGYAO
GU SHENGHONG
YANG YULAN
WANG BI
Yunnan Observatory
Chinese Academy of Sciences
Kunming
P R of China
Reference
Yamasaki A Jugaku J and Seki M Astron J
COMMISSIONS AND OF THE IAU
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Number
Konkoly Observatory
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Octob er
HU ISSN
ECLIPSING BINARY V Cyg S
FORMER Ins a TYPE VARIABLE
The eclipsing binary V Cyg S was discovered in the course of Sonneb erg
survey program Ahnert et al The following light elements were determined
d
Min : E
Ahnert et al determined the initial ep o ch and the p erio d close to reality
but later on these elements were disregarded Kukarkin et al included V
Cyg in the Second Edition of the General Catalog of Variable Stars GCVS as an RW
Aur type variable In the Third and Fourth Editions of the Star was marked as an
Ins a type variable of B sp ectral type Kholop ov supp osed V Cyg to b e a
member of the Cyg T asso ciation Filipiev did not nd any light variability of
the star Pugach observed three minima of V Cyg and prop osed a new formal
d
p erio d of P : Though those moments of minima are well describ ed with the
ab ove mentioned ephemeris Moreover Pugach noted the presence of a shallow H
absorption line pro le
In V Cyg was included in Mt Maidanak ROTOR observational program
Shevchenko to investigate its variability
Our observations of V Cyg were made using the m re ector equipp ed with
UBVR pulse counting photometer UBVR magnitudes were obtaine during obser
vational seasons
We have recorded times of the primary minimum and calculated the improved ele
ments using all data of other authors
d
MinI JD Hel : E
Julian Dates of the minima with phases and UBVR data are listed in Table I The
folded V curve and its primary minimum are shown in detail in Figures and resp ec
tively
We have not enough data in the minimum to make an orbital solution Nevertheless
we made a preliminary analysis of the light curve
We supp ose the following
There is a partial eclipse at the minimum
The secondary fainter star is passing in front of the small B primary in the primary minimum see Figure
Table I
JD Hel Phase V U B B V V R
mean light
in maximum
Figure The V curve of V Cyg
Figure The minimum of V Cyg
Taking into account the B sp ectral type of V Cyg we consider the total mass of
the binary system not to b e less than M
Then R > R R > R M < A M m> r> kp c
v v
It takes ab out two more observational seasons to obtain the primary minimum in detail
Authors thank the C EE ESO committee and ISF Foundation for nancial supp ort
of ROTOR program
S Yu MELNIKOV
V S SHEVCHENKO
K N GRANKIN
Astronomical Institute of Ac Sci
Uzb ekistan Astronomical st
Tashkent Uzb ekistan
References
Ahnert P Ho meister C Rohlfs E van de Voorde VSS No
Filipiev G K Astron Tsirk No
Kholop ov P N Sov Astr A Zhu
Kukarkin B V et al General Catalog of Variable Stars GCVS I I Moscow
Nauka
Pugach A F IBVS No
Shevchenko V S Herbig Ae Be stars Tashkent Fan
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
IS PRAESEPE KW ACTUALLY A DELTA SCUTI STAR
The Scuti stars are nearly a hundred radial and non radial pulsators lo cated close
to the Main Sequence at the Cepheid instability strip Ro dr guez et al b eing
ob jects of extreme interest for asteroseismic investigations Brown and Gilliland
These variables show short p erio ds typically shorter than hours and longer than
half an hour and luminosity amplitudes ranging from several tenths of a magnitude to
a lowest level which is continuously decreasing from one day to another frequency p eaks
with amplitudes of the order of mmag have b een found in recent campaigns
In the last few years extremely go o d observational results have b een obtained on
Scuti stars esp ecially on their multi perio dic character which seems to b e more the rule
than the exception Breger On the other hand pure theoretical work is also
currently undertaken on the sub ject see e g Dziembowski
A connection b etween high quality frequency sp ectra which are b eing obtained and
theoretical work carried out in order to interpret them is b eing pro duced Goupil et al
P erezHern andezet al
On the fourth photometry campaign of the STEPHI network the Scuti like stars
BN Cnc HD and BUC nc HD were simultaneously monitored during a
three week three continental run in February Belmonte et al Both stars
are members of the Praesep e cluster The constant star HD KW was chosen
as comparison star since at that moment no variability ab out it had b een rep orted
However we were really surprised when we realized that KW had b een discovered
as a p ossible Delta Scuti star by Rolland et al with observations p erformed in
February a year b efore our campaign
Rolland et al obtained observations over two distant nights ve hours on JD
and ve hours on JD The resolution in frequency asso ciated to such
a window is very close to the one obtained for one single night of hours Hz We
thus have considered that the error bar on the frequency determined by Rolland et al
was of order Hz
We have lo oked for this Hz oscillation frequency in our data In principle we
noticed that some frequency p eaks that we had identi ed as p ossible noise signals in
previous analyses were found at the correct frequency and with signi cant amplitudes
Figure
On the other hand during the STEPHI IV analysis we had pro duced and analysed
three di erent di erential light curves BU Cnc HD BN Cnc HD and BU
Cnc BN Cnc The comparison of these three light curves was used to ascertain which
oscillation frequency corresp onds to which star
Figure Frequency sp ectra of the time series BN Comp and BU Comp for February
at Observatorio del Teide A common p eak at Hz was initially b elieved
to b e caused by noise However we now consider that it could b e related to an oscillation
frequency of the constant comparison star KW
Besides the results pro duced in Belmonte et al the presence of a p eak at
Hz was noticed in the two light curves involving the comparison star HD
and not in the third light curve The detection con dence level was around and in the
absence of further information this p eak was attributed to noise in the comparison light
curve However the discovery of a Hz oscillation frequency in this star obliged to
revise this detection
We will not go into the details of the statistical test used in the analysis of the STEPHI
campaigns This test is derived from the Fisher s test Fisher Ko en Michel
The p oint is that the con dence level attributed according to this test dep ends
on the width of the frequency range in which one exp ects to detect oscillation frequencies
For a given p eak this dep endence go es like the p ower of the frequency range ratio CL
(FR1 F R2)
CL where CL is the con dence level asso ciated with the frequency range FR
and CL with the frequency range FR This simply re ects the fact that the probability
to nd in a Fourier sp ectrum a noise p eak higher than a given amplitude increases with
the number of events considered i e with the number of indep endent frequency samples
investigated
In the STEPHI IV analysis we were lo oking for oscillation frequency in the complete
range of oscillation frequencies exp ected for Delta Scuti stars Hz to Hz
corresp onding to p erio ds from hours to minutes However if we now consider the
detection by Rolland et al of an oscillation frequency in the range Hz
Hz as completely secure con dence level and if we investigate this restricted
frequency range in the STEPHI data the con dence level of the p eak we see at Hz
(40 1450)
b ecomes
We thus conclude that the oscillation frequency detected by Rolland et al is very
probably the Hz detected in the STEPHI IV data The di erence in amplitude
b etween the two analyses mmag for Rolland et al and mmag and mmag for
the two light curves considered in the STEPHI analysis is not related to an amplitude
change of the mo de but rather it can p erfectly b e attributed to the noise which we found
to b e rather high at low frequency Consequently KW is probably a long p erio d Delta
Scuti star lo cated in the upp er part of the Main Sequence almost evolving to subgiant
where it is crossed by the instability strip
Further data will b e needed to establish its frequency sp ectrum with high accuracy
Hop efully further campaigns of STEPHI or the Delta Scuti Network will provide such
high quality data in the future
1
J A BELMONTE
2
E MICHEL
3
M ALVAREZ and
4
JIANG S Y
Instituto de Astrof sica de Canarias La Laguna Tenerife Spain
Observatoire de Meudon DASGAL URA F Meudon France
Instituto de Astronom ade la UNAM Ap P Ensenada BC Mexico
Beijing Observatory Chinese Academy of Sciences Beijing China
References
Belmonte J A Michel E Alvarez M Jiang S Y et al A A
Breger M In GONG workshop Helio and Astero seismology from the Earth and
Space R Ulrich ed ASP Conf Ser in press
Brown T M and Gilliland R L ARAA in press
Dziembowski W In GONG workshop Helio and Astero seismology from the Earth
and Space R Ulrich ed ASP Conf Ser in press
Fisher C Proc Roy Soc London A
Goupil M J Michel E Lebreton Y Baglin A A A
Ko en C ApJ
Michel E Ph D Thesis Universit eParis VI I
P erezHern andezF Claret A Belmonte J A A A in press
Ro dr guezE L opez de Co ca P Rolland A Garrido R Costa V A A in press
Rolland A Garc a Pelayo J M L opez de Co ca P Ro dr guez E Costa V DSN
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
WATER MASERS IN L
We rep ort the results of a water maser search carried out with the E elsb erg m
telescop e on Oct in the direction of IRAS sources in the L Lynds
dark cloud A Jy emission was detected in the direction of IRAS
We observed the ! GHz transition of H O with a b eamwidth of
arc sec on Oct from UTC to UTC A liquid He co oled maser receiver
was used with system temp erature in the zenith of ab out K We used the standard
channel auto correlator with bandwidths of MHz and MHz This corresp onds to
and km s resolution and and km s velocity coverage resp ectively We
observed in the p osition switching mo de with minutes integration time on b oth the OFF
and ON p ositions NGC was used for ux calibration see Baars et al
The p ositions of the far infrared FIR sources in Kun Prusti K P with
serial numbers were observed
H O maser emission was detected towards IRAS of K P The sp ec
trum obtained with MHZ bandwidth min integration time RMS noise Jy
is shown in Figure
There is a clear detection of a line at a velocity of km s which is redshifted by
ab out km s relative to the rest velocity of the cloud v km s see e g Sato
LSR
and Fukui and there is no indication for other lines i e S p eaks in the
velocity range km s km s The detected line has one gaussian comp onent
with a FWHM of km s v km s after correction for instrumental
broadening a p eak ux of Jy rms Jy and line area of Jy km s
The corresp onding luminosity assumed to b e isotropic at a distance of p c Bal azs
is L L
H O
2
The FIR colour indices of IRAS are log F F log F F
and log F F similar to other maser sources found in Cepheus by Wouterloot
R
and Walmsley W W Its total FIR ux is F S d Wm
IRAS
which corresp onds to L FIR luminosity at a distance of p c assuming isotropic
FIR radiation
Near infrared and mm continuum observations of IRAS by Rosvick
Davidge indicate that the source is p ossibly just past the protostellar phase There
is an optical jet Bal azs et al and a CO out ow Sato Fukui asso ciated
with this source The H O maser emission in the direction of this source has also b een
detected by Wilking et al and found by them to b e variable in time
The maser emission may originate in the sho cked clumps near the driving source of
the jet Interferometric observations of this source with the aim of determining a precise
p osition would help further interpretation
Figure The H O ! sp ectrum of IRAS measured on Oct in the time interval
UTC UTC
Charles M WALMSLEY
Viktor L TOTH
Max Planck Institute f ur
Lor and E otv os University
Radioastronomie
Budap est Ludovika t er
Auf dem H ugel
H Hungary
Bonn Germany
References
Baars J W M Genzel R Pauliny Toth I I K Witzel A A A
Bal azs L G Eisl o el J Holl A Kelemen J Kun M A A
Bal azs L G p ersonal communication
Kun M Prusti T A A
Lynds B T ApJS
Rosvick J M Davidge T J The JCMT Newsletter No August p
Sato F Fukui Y ApJ
Wilking B Claussen M J Benson P J Myers P C Terebey S and Wootten A
ApJ L
Wouterloot J G A Walmsley C M A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
TIMES OF MINIMUM LIGHT FOR
FOUR ECLIPSES OF FOUR BINARY SYSTEMS
We rep ort on a continuing program to observe systems suggested by Heged us
that show apsidal motion or that are likely candidates to show apsidal motion but have
not b een observed extensively enough to con rm such motion
The observations were made with the m B C re ector and Photometrics PM
CCD at the Whitin Observatory The UBVRI lter set used was describ ed by Bessell
The data were acquired via a Macintosh I Ici running IPLab Data were taken
in only one lter for a given eclipse in order to minimize the time b etween p oints This
technique along with the greater sensitivity of CCD s over PMT s and the use of com
parison stars in the same eld as the variable allows much fainter systems to b e observed
or much faster sampling on brighter systems
The data were bias dark and at corrected using standard scripts in IRAF The data
were then shifted to a common co ordinate reference frame and photometered using custom
scripts in IRAF developed by the authors Downey and Hawkins V C intensity
ratio and photometric errors were then calculated with the SC spreadsheet
Once V C intensity ratios had b een calculated the times of minimum light and stan
dard errors in Table were calculated via the metho d of Kwee and van Woerden
using a program written by Ghedini This algorithm has b een shown to give the
most accurate estimation of conjunction for asymmetric or distorted light curves Caton
The comparisons used are listed by their co ordinates from version of the GSC
CD ROM Ep o ch J All comparisons were compared to two check stars and found
to b e stable within the photometric errors over the time scale of the observations Since
the data were only intended for timing analysis they were not transformed to Johnson
standard magnitudes
Table
System Type of HJD Standard Comparison Filter
Eclipse Error Co ordinates
h m s
AP Tau Secondary I
XX Cas Primary R
XZ And Primary I
V Cyg Secondary R
Figure
Figure is a light curve of XZ And near the time of minimum light showing the low
scatter and large number of p oints attainable with a CCD system
We would like to thank Priscilla Benson Kristin Laudadio Molli Moss Catherine
Sinnott and Sarah Weisman for their kind assistance in the observations of XX Cas and
XZ And This research was supp orted in part by a grant from the W M Keck Foundation
to the Keck Northeast Astronomy Consortium
R Lee HAWKINS
Kyle F DOWNEY
Department of Astronomy
Department of Astronomy
Whitin Observatory
Thompson Physics Astronomy Lab
Wellesley College
Williams College
Wellesley MA
Williamstown MA
USA
USA
References
Caton D B Bul l A A S
Bessell M S P A S P
Downey K F and Hawkins R L in preparation
Ghedini S Software for Photometric Astronomy Willman Bell Richmond VA p
Heged us T Bul l Inform CDS
Kwee K and van Woerden H B A N
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC PHOTOMETRY OF THE SHORT PERIOD
ECLIPSING BINARY HW VIRGINIS
During a UBV survey of UV bright ob jects HW Vir BD was discovered to
b e an eclipsing binary P days by Menzies and Marang As a part of
or b
this survey Berger and Fringant obtained sp ectroscopy of HW Vir and classi ed
it as an sdB star Menzies obtained UBVRI light curves of this system and then
Menzies and Marang analysed these light curves by WD co de They also measured
the radial velocity of the primary star and calculated the absolute dimensions of the
comp onents Woo d et al also made UBVR photometry of the system and analysed
the light curves using WD co de In the recent annual rep ort of SAAO Marang and
Kilkenny announced that HW Vir shows a de nite p erio d decrease
We included HW Vir in our observing program in and observed the system on one
night in one night in and seven nights in Di erential observations with
resp ect to the comparison star BD were obtained with the cm Maksutov tele
scop e of Ankara University Observatory We used an OPTEC SSP A photometer head
which contains a side on R Hamamatsu photomultiplier We used BD as
a check star and the magnitude di erences b etween the check star and comparison star
were constant within probable errors of and in U B and V bands
resp ectively The light curves formed by these di erential observations in the sense vari
able minus comparison are shown in Figure for di erent lters with their resp ective
B V color curve U observations are shifted vertically by mag Di erential atmo
spheric extinction and helio centric corrections were made The phases of the light curves
were calculated with the light elements
d
HJD Min I E
We derived ten mean times of minima from the new observations six primary four
secondary by using the well known metho d of Kwee Van Woerden The new
estimates in di erent lters and their mean values are listed in Table I Mean times of
minima and their mean errors were generated with the formula
P
t
i
i
i
t
P
min mean
i
i
and
P
mean
i
i
Light curves in all lters exhibit a large re ection e ect as mentioned b efore by several
authors In all wavelength bands there is a shoulder of extra light in phase
interval which may b e interpreted as a mass transfer e ect
Figure Figure
Table
Min HJD min Mean err Filter HJD Min mean Std err Obs
Type
I V SS
I B
I U
II U ZM
II B
II V
II B BA
I V BA
I B
II B SO
II V
II U
I U SO
I B
I V
II B BG
II V
I V BG
I B
I V BG
I B
I B BG
Observers SS S Selam ZM Z M uyessero glu BA B Albayrak SO S Ozdemir
BG B G urol
We collected all available times of minima from the literature and constructed the
O C diagram which is shown in Figure The E ep o chs were calculated with the light
elements given by Menzies and Marang as
d
HJD Min I E
Both primary and secondary times of minima follow the same trend of O C variation
which indicates zero eccentricity for the binary orbit The O C diagram shows a clear
rapid p erio d decrease which can b e interpreted as active mass change b etween comp onent
stars But Wlo darczyk p ointed out from his analysis of their own light curves
b oth comp onents are well lo cated inside its Ro che lob e and he suggests that p erio d
changes most likely are resulting from are extended common envelope remaining after
the giant phase Only the future accurate observations will help to settle the true nature
of this p erio d variation
We give our sp ecial thanks to the observers and to Z M uyessero glu for making his
observing computer co de available to us
Birol GUROL
Selim SELAN
Ankara University Observatory
Science Faculty Tando gan
Ankara Turkey
References
Berger J Fringant A M A A
Kilkenny D Harrop Allin M Marang F IBVS No
Kwee K K van Woerden H BAN
Marang F Kilkenny D Ann Rep SAAO p
Marang F Kilkenny D IBVS No
Menzies J W Ann Rep SAAO p
Menzies J W Marang F Eds J B Hearnshaw P L Cottrell Instrumentation
and Research Programmes for Small Telescopes p
Wlo darczyk K private communication
Woo d J H Zhang E H Robinson E L MNRAS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
THE SPOTTED YOUNG SUN HD EK Dra
HD EK Dra is a young single solar type star with a rotational p erio d of
d
approximately Its U V W space velocity comp onents km s are
very close to those of the Pleiades cluster making it a probable member
of the Pleiades moving group of young stars with an age of Myr So derblom
Clements This star is part of a program b eing carried out at Villanova University
called The Sun in Time The program involves multiwavelength observations of single
G G V stars with ages ranging from Myr to Gyr These stars are suitable
proxies for the sun at several stages of its life history from the zero age main sequence
ZAMS to the very late terminal main sequence TAMS phase Dorren Guinan
a
HD dG B V T K age Myr provides a lo ok at
ef f
the sun shortly after it arrived on the main sequence Dorren Guinan b It has a
very active chromosphere and transition region which are consistent with its youth and
rapid rotation Furthermore in HD was detected as an X ray source during
ROSAT p ointed observations with an X ray luminosity of L keV erg s
x
or ab out times stronger than the Sun Dorren Guinan The X ray emission
probably originates from the stellar corona while the UV emission features are asso ciated
with the chromosphere corona transition region of the star Dorren Guinan b
The b est t to the X ray energy distribution indicates a two temperature comp onent
corona with T K and T K Dorren G udel Guinan
In this star was discovered to have low amplitude Amp V light variations
d d
with a p erio d of Dorren Guinan b These p erio dic variations increase
in amplitude with a decrease in wavelength and are assumed to b e rotational mo dulation
d
due to the presence of co ol starsp ots In that case the photometric p erio d
represents the stellar rotational p erio d HD now has a variable star designation of
EK Draconis Kazarovets Samus Goranskij
Photo electric photometry was obtained from to the present for HD in
UBV ubvy and H wide and narrow bandpasses with Automatic Photo electric Telescopes
APTs lo cated at Mt Hopkins Arizona The data presented in this rep ort has come
from the Four College Consortium FCC m APT The photo electric observations
were carried out relative to the nearby comparison star HD V B V
F and check star HD V B V F IV and followed
the usual pattern of sky comparison check variable comparison sky with each measure
lasting seconds The e ects of di erential atmospheric extinction were removed using
extinction co e cients determined from the observation of standard stars Normal p oints
were computed for the observations of each night Typically each normal consists of
individual sec measurements
Figure Photometric variations of HD versus phase Each
lter was t with a mo del solid lines on gure using Binary Maker
Table Sp ot Parameters for HD
Assumed Quantities
Inclination i
P d
r otation
a
T K
photospher e
b
Limb Darkening Coe cients
x
x
Determined Quantities
Temperature Radius Longitude Latitude
K
Sp ot
Sp ot
c
Total Sp otted Area
a
From dG sp ectral type
b
Al Naimiy
c
In terms of the total surface area of the star
The data discussed here represents nights over the p erio d January UT
through February UT Nightly means were calculated and phases were computed
d
using an arbitrary starting helio centric Julian Date and a p erio d of The data were
then normalized to intensity units and plotted in intensity versus phase
Figure shows the nightly mean di erential magnitudes for the y band A and
the u band A The di erential yellow light curve has a broad primary minimum
extending from P to P The light amplitude of the yellow curve is '
mag For the u lter the shap e is very similar to the yellow curve but the
light amplitude is greater ' mag The intermediate lters violet A and blue
A have similar shap es and amplitudes which fall b etween the yellow and ultra violet
curves
The ts for HD were done using Binary Maker a synthetic mo deler for
binary star systems Bradstreet with the second comp onent essentially turned
o given a very low mass and temp erature in order to mo del a single rotating star
The mo del consists of two large mid latitude sp ots separated by in longitude The
total area sp otted is ab out of the stellar surface area The sp ots were assumed
to b e circular and to have the same temp erature Table gives a summary of the sp ot
parameters used in the mo del
The temp erature di erence b etween the sp ots and the photosphere was determined
to b e K The mo del was t for several di erent starsp ot temp eratures and
radii in the y band A and then compared with the u band A to cover the
full range of wavelength dep endence in the data The mo dels that b est t to b oth colors
were in the range K This solution was found to t the other light curves at the
intermediate wavelengths The uncertainty in the value results from the scatter in the
data and ambiguities in the mo del
Maureen P SCHEIBLE
Edward F GUINAN
Dept of Astronomy and
Astrophysics
Villanova University
Villanova PA U S A
References
Al Naimiy H M Astrophys Space Sci
Bradstreet D H Binary Maker Light Curve Synthesis Program Contact
Software Norristown PA
Dorren J D Guinan E F BAAS
Dorren J D G udel M Guinan E F ApJ submitted
Dorren J D Guinan E F a The Sun as a Variable Star Solar and Stel lar
Irradiance Variations ed J M Pap Cambridge Univ Press p
Dorren J D Guinan E F b ApJ
Kazarovets E V Samus N N Goranskij V P IBVS No
So derblom D R Clements S D AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC OBSERVATIONS OF AB DORADUS
AB Doradus is a chromospherically active rapidly rotating single star that has b een
extensively observed for over years Photo electric measurements were made at Mt
Molehill in November and in January A
mm f Schmidt Cassegrain Telescope an RCA b P M T standard Johnson B
V lters and DC electronics were used to make the observations AB Doradus was
monitored continuously in two colours using di erential photometry Measurements of
the comparison star and check were made regularly at ab out minute intervals
Reductions to the UBV standard system were carried out in accordance with the
metho ds describ ed by Henden and Kaitchuck
Figure The two light curves collected in November top and
in January b ottom The square symbols are January
Figure The B V plotted against phase November top and
Januar b ottom The square symbols are January
Figure Overall light level and range of V light plotted against year
Each bar gives the range and light level at the observed ep o chs
Table Check Star HD
Date n V mag S D B V S D
individual nights
J D
J D
J D
J D
J D
S D standard deviation
The observing sequence was sky comp var comp sky var check comp sky etc Check
star measurements Table had a standard deviation of or less Each data p oint
on the light curve is the sum of three sec integrations Both the November and
January light curves have amplitudes of approximately magnitudes Figure The
more complete light curve for January Figure b shows what app ears to b e a
second sp ot at phase Figure shows the amplitude of the light curves and the phase
angle of the sp ots in relation to each other There is a three hour phase shift b etween the
November and January light curves This corresp onds to a linear phase shift
of : p er day when using the p erio d of days derived by Innis et al By
changing the p erio d to days the two data sets can b e brought back into phase The
January Figure b light curve is a comp osite of ve nights The rise was observed
on January and the fall on January thirteen days apart and the resulting light curve
is distorted The rise and the fall on November Figure a were observed during
one observing session and therefore would b e more accurate The B V Figures a
b shows an apparent drop from to coinciding with the minimum of the V light
curves Figure is a plot of the overall brightness and amplitude of AB Doradus since
Each bar gives the range and light level at the observed ep o chs
Since observations started at Mt Molehill in December of AB Doradus has b een
steadily increasing in brightness the light curves for November and January
are in agreement with this
Marc BOS
Mt Molehill Observatory
a Hutton Street Otahuhu
Auckland New Zealand
References
Henden A A Kaitchuck R H Astronomical Photometry Van Nostrand Reinhold
Innis J L Thompson K Coates D W Lloyd Evans T Mon Not R Astr
Soc
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
A NEW V R CYCLIC CHANGE OF H in Tau
Since the late s we have monitored the ob ject The observations rep orted in this
pap er were made with the grating sp ectograph of the m telescop e at the Xinglong
Station of Beijing Astronomical Observatory during December April The
detector was a CCD with or pixels The recipro cal linear disp ersion
1
of the sp ectra was A mm at H One pixel corresp onds to A or A The
S N ratio at the continuum was > The observational and data reduction techniques
have already b een describ ed by Guo and Guo Our results showed that the H
pro les underwent a cyclic change c f Figure The December H pro le
app eared as a single emission p eak of asymmetric top and no visible central reversal
The pro les b ecome distinct double emission p eaks during It is of interest to
note that the April pro le b ecome again a single emission p eak such as on
December In addition the V R ratio of H was larger in equal to around
the b eginning of and less during November and Octob er than Table
lists the results of the H measurements in the di erent observing p erio ds Throughout
our observations no appreciable change in the H pro les obtained within each night has
b een detected Hence we show only the mean pro le measurements for each given night
It can b e seen from the table that the equivalent width W and the full width at half
maximum FWHM reached the maximum when the violet emission comp onent is equal
to the red one and that the intensities I of the violet emission comp onent declined
v
gradually while the intensities I of the red one rose slowly during our observing p erio d
r
Table
Date No of W FWHM I I I
v a r
UT pro les A A
Dec
Oct
Dec
Dec
Feb
Feb
Nov
Nov
Oct
Apr
? values in paranthesis are central intensity of the emission line
Figure
Since the b eginning of s the cyclic variations of the radial velocity of the Balmer
absorption lines and the V R ratio of the Balmer emission lines have b een observed
successively in the star on numerous o ccasions Hub ert Deplace et al Mon et al
showed the cyclic variations had terminated and the star seemed to have entered a
new quiet phase around Our sp ectroscopic observations also indicate that the V R
cyclic variations of H had vanished since Yulian Guo et al Our results
show that after their disapp earance for several years a new V R cyclic variation of H
emerged once again at the end of and lasted for ab out years It seems that
the cyclic variations of the star were very complicated not only the duration and the
amplitude of each cycle are di erent but the cyclic variation is sometimes disapp earance
and at other times reapp earance Therefore it is necessary to make further observations
and discussions
YULIAN GUO
Beijing Astronomical Observatory
Chinese Academy of Sciences
Beijing China
References
Guo Yulian Guo Xiozhen Inf Bul l Var Stars No
Guo Yulian Huang Lin Hao Jinxin Cao Huilai Guo Zihe Gou Xiaozhen in
preparation
Hub ert Deplace A M Jaschek M Hub ert H Chambon M Th in Jaschek
M Groth H G eds Pro c IAU Symp Be stars p
Mon M Kogure T Suzuki M Singh M PASJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
A DETECTION OF MOVING BUMPS IN THE EMISSION
PROFILES OF THE Be STAR FX Lib
This star has a long history of sp ectroscopic observations Since its shell
b ecome active Long term variations of the radial velocity of the shell absorption lines
and of V R ratio of Balmer emission lines are cyclic Faraggiana Delplace and
Chambon Aydin and Faraggiana Hub ert Delplace et al Its H
pro le also underwent rapid changes on a time scale of days as well as long term changes
on a time scales of years Aydin and Faraggiana Slettebak and Reynolds
A series of CCD H sp ectra of the star were taken using the grating sp ectograph of
the m telescop e at the Xinglong Station of Beijing Astronomical Observatory during
April June The detector was a CCD with pixels The recipro cal linear
1
disp ersion of the sp ectra was A mm at H One pixel corresp onds to A The
observational and data reduction techniques have already b een describ ed by Guo and Guo
The following changes can b e found from these data
Night to night changes o ccur in the H emission pro le Figure shows three
H pro les which represent the mean pro le obtained on April and June
resp ectively It can b e seen from the gures that April H pro le app ears as a
double emission but one day later the H pro le had three emission p eaks While in the
H pro les of UMa and Dra which were observed in same two nights were not found
any changes This demonstrates that the H pro le changes of Lib are reliable It is
worth noting that the June H pro le b ecome again a double emission p eak but
the violet emission comp onent obviously weaker than red one The remarkable change
in the H pro le observed on April implies the p ossible o ccurrence of rapid
violent activity in the stellar emission envelope
H emission pro les of the star exhibit ultrarapid and as if cyclic changes
sp ectra of the star were taken on April see Figure a The H displayed change
with time It is seen at a glance that there were two red emission comp onents varying in
intensity The b ottom pro le in Figure b represents the mean pro le of these sp ectra
and the other which are formed by subtracting the mean pro le from each sp ectrum are
the line pro le residuals It is obvious that its H emission undergo es the ultrarapid
changes on a time scale of minutes
It can b e seen from Figure b that the ultrarapid variations of the H pro les resemble
the moving bumps which have b een observed at high resolution and high signal to noise
ratio in the absorption lines of some Be stars Walker et al Yang et al
Flo quet et al Bossi et al At present there were two interpretations for these
line pro le variations in Be stars photospheric non radial pulsations Vogt and Penrod
or corotating structures in the matter ab ove the stellar photosphere Harmanec
Gies Our observations showed that the H pro les had dramatic moving
features but the phenomenon was not found in HeI Therefore we may infer that
Figure Figure
the H line pro le variations could b e due to the nonuniform distribution of the cir
cumstellar matter The nonuniform distribution of the circumstellar envelope is p ossibly
related to the violent activity of the emission envelope in the star during April
Unfortunately our resolution is considerably lower and observations are limited only
to H and HeI In order to b etter understand the details of the variations and
throughly investigate the nature of the variations it is necessary to make high resolution
and high signal to noise ratio observations of di erent lines of interest at widely di erent
wavelengths
YULIAN GUO
Beijing Astronomical Observatory
Chinese Academy of Sciences
Beijing China
References
Aydin C Faraggiana R A A Suppl
Bossi M Guerrero G and Zanin F A A
Delplace A M Chambon M Th in Slettebak A ed Pro c IAU Symp
Be and Shell Stars Reidel Dordrecht p
Faraggiana R Ap Letters
Flo quet M Hub ert A M Janot Pacheco E Mekkas A Hub ert H and Leister N
V A A
Gies D R in Balona L A Henrichs H F and Le Contel J M eds Pro c
IAU Symp Pulsation Rotation and Mass Loss in Early type Stars Kluwer
Academic Publishers London p
Guo Yulian Guo Xiozhen Inf Bul l Var Stars No
Harmanec P Bul l Astron Inst Czech
Hub ert Delplace A M Mon M Ungerer V Hirata R Paterson Beeckmans F
Hub ert H Baade D A A
Slettebak A Reynolds R C Ap J Suppl
Vogt S S and Penrod G D Ap J
Walker G A H Yang S and Fahlman G G Ap J
Yang S Walker G A H Hill G M and Harmanec P Ap J Suppl
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
APT OBSERVATIONS OF SMALL AMPLITUDE RED VARIABLES
Small amplitude red variables SARVs are M giants which are pulsating with small
amplitudes < mag and with p erio ds of to days SARVs are b elieved to b e
part of a sequence of red variables extending from the so called Librae stars p erio ds
days V amplitudes typically mag to the Mira stars Along this sequence of red
variables the incidence of variability and the p erio d and amplitude of variability tend
to increase with later sp ectral type but the correlation is not an exact one
There are known and susp ected variables among the approximately M
giants in the Yale Catalogue of Bright Stars In order to clarify the variability status of
these M giants one of us JRP has b een conducting a search for SARVs using the
m teaching telescop e of the University of Toronto Percy and Fleming Percy and
Shepherd and using the American Asso ciation of Variable Star Observers AAVSO
network of photo electric photometrists Percy et al Several SARVs which had not
b een assigned to a student observer or to the AAVSO observers were monitored for one
season with an automatic photo electric telescop e APT
The seven SARVs listed in Table were monitored automatically with the Pho enix
m re ector through the APT Service of the Fairborn Observatory exactly as describ ed
by Percy Table lists the program P comparison C and check K stars
their prop erties the standard deviations of the di erential U B and V magnitudes of
the program and check stars relative to the comparison stars and the assessment of the
variability of each star A few observations were omitted for a priori reasons e g if there
was a large internal standard error if the APT quality control information indicated
that the night was a p o or one and or if the observation was incomplete The standard
deviations of the constant stars to in B and V to in U are typical
for observations of co ol stars with this telescop e
In addition to the results given in Table there are the following notes on individual
stars sample light curves are given for three stars
HR VAR YCBS The variability is marginal at b est
HR VAR YCBS The star varies on time scales of and > days Figure
there is also a distinct p eak in the p ower sp ectrum at days
HR NSV V NSV We nd a similar range The variability
is irregular with a characteristic time scale of days Figure The highest p eak in
the p ower sp ectrum is at days
HR VAR YCBS The most obvious variability is on a time scale of days
but there is some evidence for more rapid variability as well Figure
HR CV Dra V YCBS Our observations show a much smaller
range but over a limited time interval The p ower sp ectrum shows no dominant p eak
HR BY Bo o Lb V YCBS The dominant p eak in the p ower
sp ectrum is at days
Table APT Observations of Small Amplitude Red Variables
Star HR SpT V U B V Result V Period days
P M I I I constant
C G I I I constant
K G I I I constant
P M I I I variable longer
C G I I I constant
K K I I I constant
P M I I I variable
C F IV V constant
K A Vn constant
P M I I I variable shorter
C K I I I constant
K G I I I constant
P M I I I variable
C K V constant
K G V constant
P M I I I variable
C gK constant
K K I I I constant
P M I I I variable
C K I I I constant
K A V constant
Figure The V light curve HR relative to HR
The standard error of the measurements is
Figure The V light curve of HR relative to HR
The standard error of the measurements it
Figure The V light curve of HR relative to HR
The standard error of the measurements is
HR CF Bo o m YCBS The dominant p eak in the p ower sp ectrum
pg
is at days
Because of the limited span of the observations it is not p ossible to derive precise
information ab out the amplitude and time scales of the variability The observations
have however given estimates of the amplitude of short term days to months variability
which are useful for statistical purp oses Most of these stars are early M giants and the
amplitudes are relatively small and the time scales short HR for instance shows
some evidence of very short time scale variability A few of the stars show conspicuous
time scales of variability of order weeks At least two show variability on a time scale
days The origin of these long term variations is not known In general the incidence
amplitude and time scales of variability as a function of sp ectral type are consistent with previous results
Acknowledgements JRP thanks Michael Seeds for his excellent work as Principal
Astronomer for the APT Service and the Natural Sciences and Engineering Research
Council of Canada for a research grant Winnie Au was a participant in the University
of Toronto Mentorship Program which enables outstanding senior high school students
to work on research pro jects at the university
John R PERCY
Winnie AU
Erindale Campus
University of Toronto
Mississauga Ontario
Canada L L C
References
Kholop ov P N ed New Catalog of Susp ected Variable Stars Moscow Nauka
Percy J R PASP
Percy J R and Fleming D E B PASP
Percy J R and Shepherd C IAU Inf Bul l Var Stars No
Percy J R et al PASP
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
V AND UV PHOTOMETRY OF HD
m
HD is a bright V early O V O V non eclipsing binary in
the center of the op en galactic cluster NGC Thomas rep orted an ellipsoidal
variability in the V bandpass and in this contribution we communicate that photometry
supplemented by optical and UV data derived from a number of sp ectral images secured
by the International Ultraviolet Explorer IUE
Table I V di erential photometry of HD
UT V s d N Phase
March
April
m
The Thomas di erential photo electric photometry with HD V
used as a comparison star is listed in Table I N is the number of magnitude di er
ences that were averaged to obtain each tabulated magnitude di erence and s d is
their standard deviation The photometry used the V lter of the UBV system and a
P photomultiplier tub e The magnitudes were derived from capacitor charge integra
tions displayed on strip chart pap er acquired with the Lowell meter telescop e at the
Cerro Tololo Inter American Observatory A second comparison star provided a check on
the p ossible variability on HD Each tabulated magnitude di erence in Table I
HD minus HD represents an observing time interval of ab out minutes
m
Corrections for extinction did not enter into the calculations O set by in the
ordinate in order to bring it on scale this photometry app ears as triangles in Figure
m
revealing an ellipsoidal variation with an amplitude of ab out
Table I I V magnitudes and UV data from IUE images
Image Phase A A A A A A FES
SWP m
V
Column of Table II lists the image numbers of IUE sp ectra that were secured
during three consecutive p erio ds of the binary These high resolution images were obtained
by the SWP Short Wavelength Primary camera ab oard the spacecraft through the large
ap erture Phases for the photometry data in the present pap er were calculated from the
following constant perio d ephemeris kindly provided by R H Ko ch
d
Pri Min HJD E
which is consistent with the optical photometry of Thomas and the accurate radial velocity
solution of Stickland et al based on the IUE material
Figure
UV light curves were derived from the IUE sp ectral images in the following way A
square lter A A applied on a given sp ectral image integrated all ux b etween
A and A ie lter transmittance is within the bandpass and zero outside
This integrated ux was then divided by the bandwidth in this case A to yield average
mono chromatic ux in units of MFU over that bandpass These measures are listed in
column Table I I Two additional data sets derived in the A A and A
A bandpasses are also listed in Table I I This UV photometry was restricted to
the most recent large ap erture high disp ersion SWP sp ectral images since the other
archival images were obtained through the small ap erture or span a di erent LWP
sp ectral region or are of low resolution
UV magnitudes in each bandpass were computed from the listed uxes by rst multiply
ing by the bandwidth yielding uxes in FU and then calculating m l og f l ux
UV
The light curves so computed are displayed in Figure displaced in the ordinate scale
by the following quantities to bring them on scale
m
crosses A A by
m
stars A A by
m
diamonds A A by
None of the three bandpasses is contaminated by wind lines and the estimated accuracy
m
of the measures is b etter than
All three UV light curves are remarkably similar even though they span almost A
The ellipsoidal variability evidenced in the optical light curve is also present in all three
m m
UV data sets at a level of to dep ending on the signi cance attributed to the
two fainter measures near phase and to the one near phase
The Fine Error Sensor FES is an optical sensor ab oard the IUE spacecraft intended
for target acquisition rather than photometry Nevertheless each IUE image is supple
mented with FES counts from the source which were converted to the V magnitudes
listed in Table I I column using IUE Data Analysis Center IUEDAC software This
m
FES derived photometry displaced by in the ordinate scale is displayed in Figure
m
by squares The errors commonly claimed to b e clearly hide the ellipsoidal
variability revealed in the Thomas data and in the UV light curves
J C THOMAS I PACHOULAKIS
Montezuma Dr Department of Physics
Campb ell CA and Astronomy
U S A University of Pennsylvania
r d
S Str
Philadelphia PA
U S A
References
Stickland D J Lloyd C Ko ch R H Pachoulakis I and Pfei er R J The
Observatory
Thomas J C Bul l A A S
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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November
HU ISSN
CF Cas NSV
During my work on PICA project Precise Identi cation and Co ordinate Adjustment
of ab out variables I have found that CF Cas is identical with NSV
CF Cas SVS is a well known classical cepheid lo cated in the
op en cluster NGC It was discovered by Beljawsky and so on received its
nal designation Guthnick Prager From the time of its discovery the star was
included in many photometric and sp ectroscopic researches
NSV is listed as star No in a catalogue of prop er motions of stars in the
region of op en clusters NGC and NGC Ishmukhamedov Neither chart
nor equatorial co ordinates were published for this star in his pap er Later it was included
in the New Catalogue of Susp ected Variable Stars Kholop ov et al
While working on eld variable stars around QX Cas I have noticed that co ordinates
rep orted in NSV for NSV are ab out north of the star I have earlier identi ed as
QX Cas To nd additional information usable for correct identi cation I have checked
Ishmukhamedov s pap er the only one found for NSV at all He gives there
the used pro cedures and also a catalogue listing star sequence number photographic
magnitude approximate xy co ordinates in mm prop er motion comp onents and a short
remark From the xy co ordinates and magnitudes I have plotted a chart covering eld
around star No see Figure in the middle Comparison of this plot with scanned
pap er copy of POSS plate O Figure left gave following results
star No without var remark was identi ed as NSV
star No without var remark was identi ed as CEab Cas
star No with var remark was identi ed as QX Cas
star No NSV with var remark has no suitable optical counterpart at the
plotted p osition
From this it is clear that NSV cannot b e identical with QX Cas From the com
parison one can also see that the co ordinates given in NSV for NSV are erroneous
So where is this star
Another comparison of plot and scanned POSS shows that while star No is sup er
uous in it s lo cation one bright star by chance variable CF Cas is missing on the plot
Close lo ok shows that plotted stars do NOT exactly match their counterparts on the sky
This can explained partly by the fact that catalogue xy co ordinates are only approximate
having the precision stated to b e mm but in fact a bit worse But such errors can t
help us Therefore I have checked the whole catalogue for evident misprints and found
of these stars Nos and out of
listed stars I have found also some other misprints in the text part so I have checked
the p ossibility there is a misprint in xy co ordinates of stars No and I have found a
solution The printed y co ordinate is : while at : and same x co ordinate is the
Left Scanned POSS plate O The picture was pro cessed after scanning to elimi
nate the faintest stars Middle Plot from catalogue of Ishmukhamedov The op en
circle marks the p osition of star No on its original place Right Plot from GSC
Arrowed stars are CEab Cas CF Cas QX Cas and NSV while crossed circles
mark the bad GCVS and NSV p ositions for QX Cas and NSV The area covered
by all the charts is the same ab out with north up
Table Comparative table of original data for NSV GSC GSC
CF Cas and QX And CF Cas and QX And Data concerning NSV are from NSV
data for CF Cas and QX Cas are from GCVS data for CF Cas Plaut are by Plaut
and data for GSC for GSC and GSC are from GSC
Photometric system co de for GSC represents the Ko dak I Ia D plate with W l
ter Co ordinates printed in italics were computed from the ab ove stated data sources
bright star having up to this moment no counterpart in catalogue I supp ose these stars
are identical for these reasons
after correction the match with real star is quite go o d
misprints are often in the pap er of Ishmukhamedov
star No has a var remark and CF Cas is variable
the photographic magnitude of star No do es not contradict B magnitudes of CF Cas
Summary information can b e found in Table Following cross identi cations are
valid
h m
CF Cas SVS NSV Vat ph No
GSC
QX Cas SVS CSV GSC
Jan MANEK
Stef anikObservatory
Pet r n
Praha Czech Republic
Internet observ earn cvut cz
References
Beljawsky S Astronomische Nachrichten
Guide Star Catalogue v The Space Telescope Science Institute Baltimore Mary
land USA on CD ROM
Guthnick P Prager R Astronomische Nachrichten
Ishmukhamedov Kh Circular Tashkentskoi Astr Observatorii No
Kholop ov P N et al New Catalogue of Suspected Variable Stars Nauka Moscow
Kholop ov P N et al General Catalogue of Variable Stars th ed Nauka Moscow
Plaut L Astronomy Astrophysics Suppl
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC OBSERVATIONS OF THE CLOSE
ECLIPSING BINARY VW CEPHEI
Di erential photo electric photometry of the close eclipsing binary VW Cephei SAO
M B V was carried out during the summer at the
v
station of Capanne di Cosola AL Italy A total of data p oints were collected in the
instrumental V color
The comparison star was HIC SAO M B V
v
and the check one was HIC SAO M B V
v
Photometry of VW Cephei was carried out with a mm Schmidt Cassegrain f
telescop e equipp ed with a solid state photo electric photometer Optec SSP op erating in
the Johnson Morgan B and V bands
Five helio centric times of minimum were computed using the available observations
The helio centric times of minimum obtained with the Minimum Entropy SOP metho d
MEMSOP Gaspani a are listed in Table The O C residuals computed with
resp ect to the ephemeris Navratil
d
T HJD : E
min
are listed in the same table It is interesting to remark that all the residuals are system
atically negative This means that the ephemeris must b e up dated in order to satisfy
our data
On the other hand the moments of minima observed by Abb ott et al as well as
Vink oet al give as yet negative residuals of comparable magnitude with resp ect
to the ephemeris
Therefore we computed an up dated ephemeris making use of our data as well as the
recent data of Navratil Abb ott et al and Vink o et al in order to
increase the accuracy of the least squares t
On the basis of the available times we obtained the following least squares t
d
Min I HJD : E
Table shows the residuals computed with resp ect to the ephemeris
VW Cephei is an active close binary whose light curve shows temp oral changes This
variability has b een interpreted as arising from the presence of dark starsp ots lo cated
mainly on the photosphere of the more massive star of the system Bradstreet and Guinan
After these premises it seems to b e useful to try to recover the true light curve from
the noisy data in order to show changes in the height of the maxima depth of the minima
and photometric p erturbations
Figure Light curve of VW Cephei The solid line is the signal restored
with the optimum Wiener lter and the squares are the individual data p oints
Table Helio centric times of minimum
Observed Minima E O C
Min I
Min I
Min I I
Min I
Min I
In order to recover a convenient estimate of the true signal from the noisy data we pro
cessed the noisy phased data with a signal restoration technique based on the Optimum
Wiener Filter Theory Gaspani b
Figure shows the restored light curve graphed as a solid line across the original data
p oints and Table shows the results obtained
Table Residuals from the ephemeris
Ep o ch Observed time Residual Source
E of minimum O C
JD
a
a
a
b
c
b
b
c
c
c
c
d
d
d
a Navratil b Abb ott et al c Aluigi et al present pap er d Vink o
et al
Table
Delta V
VW Cep HIC
Primary Minimum
Maximum I
Secondary Minimum
Maximum I I
Marco ALUIGI
Gianni GALLI
GEOS Promenade Venezia
GEOS Promenade Venezia
F Versailles France
F Versailles France
Adriano GASPANI
Osservatorio Astronomico di Brera
Via Brera Milano Italy and
GEOS Promenade Venezia
F Versailles France
References
Abb ott B Rumignani D Inf Bul l Var Stars No
Bradstreet D Guinan E in Active Close Binaries ed C Ibanoglu pag
Gaspani A a The algorithms useful in nding the extrema of the light curves
Talk presented to the Second GEOS Workshop on the Eclipsing Variable Stars and
their Data Pro cessing S Pellegrino Terme Italy May
Gaspani A b The pro cessing and the restoration of the light curves Talk pre
sented to the Second GEOS Workshop on the Eclipsing Variable Stars and their
Data Pro cessing S Pellegrino Terme Italy May
Navratil M Inf Bul l Var Stars No
Vink o J G al J Szatm ary K Kiss L Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
NEW BRIGHT MEDIUM AND HIGH AMPLITUDE VARIABLES
DISCOVERED BY THE TYCHO INSTRUMENT
1
OF THE HIPPARCOS SATELLITE
The HIPPARCOS pro ject will discover a large number of hitherto unknown variable
stars as a side result of a primarily astrometric satellite for a description see Perryman
and references therein The HIPPARCOS main instrument is exp ected to detect
low amplitude variability in several stars while the TYCHO instrument will scan
million stars down to ab out B for medium to high amplitude variations The
four year lifetime of the satellite ended in August The reduced data including the
individual photometric measurements of all observed stars will b ecome available to the
general astronomical community in
Here we present a small list of new bright medium to high amplitude variables that
b ecame obvious during routine astrometric pro cessing of the TYCHO data All were
checked for known counterparts in the General Catalogue of Variable Stars GCVS in
the New Catalogue of Susp ected Variables NSV and in the ve name lists of newly
designated variable stars issued since IBVS Ground
based follow up observations are encouraged to clarify the nature of the stars and to
assess the quality of these preliminary TYCHO results The amplitudes as observed by
TYCHO are mostly ab ove magnitude with of them exceeding magnitude
The new variables are listed in Table The columns of the table contain in turn
the designation of the star in the Space Telescope Guide Star Catalogue the J p osi
tion the observed range of variability in the T magnitude de ned b elow and remarks
For each of the stars there are of the order of TYCHO observations in two wavelength
bands close to B and V resp ectively Nevertheless light curve classi cation from these
data is very di cult b ecause the observations are extremely unevenly distributed in time
Table therefore gives only rough indications on the character of the variability
Among the stars in Table there are six NSV stars indicated in the remarks
column The TYCHO measurements thus con rm the susp ected variability of these
ob jects
Figures and show the observed light curves for two of the NSV ob jects as an
illustration of the TYCHO data The T magnitude is a broad band optical magnitude
derived from the sum of the photon counts in the TYCHO B and TYCHO V photometric
channels under the condition that T B V if B V See Halbwachs et al for
more details
Acknowledgements This work was supp orted by Bundesministerium f ur Forschung
und Technologie Deutsche Agentur f ur Raumfahrtangelegenheiten DARA Pro jects
and and by the Danish Space Board The results presented here
are based on the collab orative e ort of the HIPPARCOS and TYCHO scientists and
engineers scattered all over Europ e
Based on observations made with the ESA Hipparcos satellite
Table Results on the new variables
GSC TIC Id R A Dec T max T min Remarks
h m s
:
NSV
days p erio d
p erio dic days
NSV
NSV
days p erio d
NSV
days p erio d
SRb type
p erio dic
NSV R CrB type
NSV
eclipsing
slowly variable
eclipsing
p erio dic
Figure TYCHO light curve of GSC NSV All raw observations of
the star by TYCHO are shown The di erent symbols denote di erent ap ertures of the
instrument The T magnitude is de ned in the text The strong clumping of the p oints
is an unavoidable consequence of the primarily astrometric measuring schedule of the
HIPPARCOS satellite The scatter of the p oints within each clump is due to the random
measurement errors They will b e somewhat smaller after the nal photometric reduction
of the TYCHO data The variability of this susp ected variable is con rmed by the data
shown here
Figure TYCHO light curve of GSC NSV Same remarks as for Figure
Valeri MAKAROV
Ulrich BASTIAN
Erik HOEG
Volkmar GROSSMANN
Andreas WICENEC
Cop enhagen University Observa
tory Cop enhagen Denmark
Astronomisches Rechen Institut
Heidelb erg Germany
Astronomisches Institut
der Universitaet Tuebingen
Germany
References
Halbwachs J L et al Astron Astrophys
Perryman M A C Nature
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
FIVE NEW DHK VARIABLES
My continuing photographic patrol has resulted in the discovery of four more variable
stars that are not listed in the General Catalogue of Variable Stars Kholop ov et al
or the subsequent Name Lists of the Variable Stars Kholop ov et al
Kazarovets and Samus Kazarovets et al Nor are they listed in the New
Catalogue of Susp ected Variable Stars Kholop ov et al In addition a fth new
variable star DHK was discovered photo electrically during observations of Nova Aql
Green Positions and preliminary magnitude ranges types and p erio ds are
given in Table which continues the list in Kaiser
I have con rmed photo electrically the variability of DHK and David B
Williams has examined DHK and on the Harvard patrol plates con rmed their
variability and provided the photographic magnitude ranges cited in the Table Marvin
E Baldwin has visually monitored the new eclipsing binaries detected additional minima
and help ed to determine the p erio ds The observations of each star will b e published when
analysis is completed
DHK were discovered using photographs taken with the newly completed Auto
matic Photographic Patrol APP The APP is an automated camera in equatorial mount
controlled by computer It will b e describ ed in detail elsewhere
Table
Var Designation RA Dec Range Type P days
h m s
DHK pg SR
GSC
DHK SAO V Lb
HD
PPM
DHK pg SR
GSC
DHK SAO V EB
BD
PPM
DHK SAO V EA HD
The APP is supp orted by a grant from NASA administered by the American As
tronomical So ciety for which I am most grateful I would also like to thank David B
Williams and Marvin E Baldwin for helping to con rm the variability and determine the
p erio ds of these stars The variables were detected using a pro jection blink comparator
PROBLICOM as describ ed by Mayer
Daniel H KAISER
Washington Street
Colombus IN
USA
References
Green D W E I A U Circ No
Kaiser D H Inform Bul l Var Stars No
Kazarovets E V and Samus N N Inform Bul l Var Stars No
Kazarovets E V Samus N N and Goranskiy V P Inform Bul l Var Stars
No
Kholop ov P N editor et al New Catalogue of Susp ected Variable Stars Moscow
Kholop ov P N editor et al General Catalogue of Variable Stars Moscow
Kholop ov P N Samus N N Kazarovets E V and Perova N B Inform Bul l
Variable Stars No
Kholop ov P N Samus N N Kazarovets E V and Perova N B Inform Bul l
Variable Stars No
Kholop ov P N Samus N N Kazarovets E V and Perova N B Inform Bul l
Variable Stars No
Mayer B Sky and Tel
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
1
A FLARE EVENT ON HR
HR SAO sp ectral type B I I I I I V was not known as a variable
It is even listed as a photo electric standard with con rmed long term stability in the
Hipparcos Input Catalogue Turon et al The star was used for more than ten years
as comparison star to the Be star V Mon Vogt Sterken in the framework of
the Long term Photometry of Variables LTPV pro ject Sterken HR also
gured as a standard star for the LTPV pro ject until when it suddenly brightened
m m
by ab out in the y b and v bands and by in u As shown in Fig this ash like
activity is mo dulated with a p erio d slightly longer than one month suggesting rotation
of a hot sp ot
Figure
1 BASED ON OBSERVATIONS CARRIED OUT AT THE ESO LA SILLA OBSERVATORY
Unfortunately this increased activity approximately coincided with the end of the
observations of the star so that only two cycles have b een monitored Only a few p oints
have b een obtained in but they show that the star was still active
Detailed analysis of this are and of the previous microvariability of HR is b eing
carried out We plan to secure more photometric and sp ectroscopic observations of this
ob ject in the following months Photometric monitoring of HR by other observers
with sp ecial emphasis towards the determination of the duration of the active state is
strongly encouraged
All data used here will b ecome available in the course of through the CDS Data
Center in Strasb ourg
J MANFROID
C STERKEN
Institut d Astrophysique
University of Brussels VUB
Avenue de Cointe
Pleinlaan
B Li ege Belgium
B Brussels Belgium
Belgian Fund for Scienti c Research NFWO
Belgian Fund for Scienti c Research FNRS
References
Sterken C The Messenger
Turon C Cr ez e M Egret D et al The Hipparcos Input Catalogue ESA SP
Vogt N Sterken C Inf Bull Var Stars
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
THE LONG TERM PHOTOMETRIC BEHAVIOUR OF THE
CATACLYSMIC BINARY HX PEGASI
The photometric history of HX Pegasi has b een unclear until now Green and Kris
tian b elieved from three scattered observations the star to have had remained
m
bright near V from July to Octob er at least Eachus and Liller
m m
found it irregularly varying b etween B : and : with no evidence of nova like
activity on Harvard plates of years I Meinunger was not able to detect
the star ab ove threshold of Sonneb erg Sky Patrol exp osures this was however b ecause
she searched at a wrong p osition that has nothing to do with the misprint in the heading
of her article Greenstein et al called the star erratically variable Ringwald
in the course of a thorough sp ectroscopic investigation caught the ob ject during a
rapid ascent of its brightness in one night followed by a decline in the next one
Moreover the star has b een included erroneously in the listings of nearby stars of
Gliese and Jahreiss and of Petit b ecause McCo ok and Sion and
others to ok the ob ject for a white dwarf of th apparent magnitude
As this binary deserves sp ecial interest b ecause of its probable sdK secondary I have
determined its brightness on a sample of almost Sonneb erg Sky Patrol plates taken
since mainly by H Huth and B Fuhrmann and I came to the following results the
m
long term light curve is characterized by numerous dwarf nova like eruptions up to : pg
Figure The Mt Wilson magnitude system of Selected Area served as a standard
From this light curve and from statistical considerations after Wenzel and Richter
a mean cycle length C of ab out days can b e derived Strong secondary uctuations
range mag time scale hours to days are observed during several high states Figure
We did not nd any short full range eruptions of a length of the order of one day But as
this might b e attributed to the rather limited length of our sample the nature of the rapid
decline observed by Ringwald is still undecided If we take into account the faint
m
observations of Greenstein B : and the minimum data of Eachus and Liller
m m
m : an amplitude of ab out : pg can b e deduced This is rather large
pg
a value as compared with an average taken from the Kukarkin Parenago relationship for
dwarf novae e g Richter and Br auer at C days Far reaching plates are not
at our disp osal We hop e that CCD observations which we have b een p erforming at one
of the Sonneb erg cm mirrors since Octob er will clear up the low state b ehaviour
and whether there are eclipses
I thank the German Bundesministerium f urForschung und Technologie for funds under
contract No S A
W WENZEL
Sternwarte
D Sonneb erg
Germany
References
Eachus L J and Liller W IAU Circ No
Gliese W and Jahreiss H Astron Astrophys Suppl Ser
Green R F and Kristian J IAU Circ No
Greenstein J L Astron J
Greenstien J L Arp H C and Shectman S Publ Astron Soc Paci c
McCo ok G B and Sion E M Vil lanova Univ Obs Contr No
Meinunger I Mitt Ver anderl Sterne Sonneberg
Petit M Inf Bul l Var Stars No
Richter G A and Br auer H J Astron Nachr
Ringwald F A Thesis Dartmouth College
Wenzel W and Richter G A Astron Nachr
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
ECLIPSE CURVES OF UX UMa IN
UX UMa is considered as an example of relative orbital stability for an interacting
binary although the shap e of its light curve is quite variable Besides eclipses and ickering
Mandel prop osed that the orbital p erio d itself of this eclipsing binary varies with
a p erio d of days
The presented photo electric data of UX UMa were obtained during nights at the
end of December and at the b eginning of January The observations were
carried out with a m telescop e of Mt Suhora Observatory Poland equipp ed with a
double b eam photometer and an autoguider Kreiner et al In order to satisfy the
requirement of the two channel photometer that the distance b etween a variable and a
comparison star to b e b etween and arcmin we used the star marked B in Figure
as a comparison and BD marked N and BD marked C as
check stars Figure shows that the star B is constant
The data were phased according to the ephemeris of Mandel
MIN J D Hel E
Some of our eclipse curves are presented in Figure On the right side on every curve
is the cycle number introduced in Table down The magnitude di erence in the sense
comparison variable on the vertical axis is relative to the central curve in every colour
The other curves are moved up or down to get a go o d visibility The U curves are omitted
from Figure b ecause their quality is to o p o or
Figure
Table includes the observed times of minima with the errors of their determination
and resp ective O C values according to the ephemeris
Table
Cycle Minima
number E Filter J D Hel O C
no
no
no
no
no
U
B
V
B
V
B
V
B
V
U
B
V
B
Analysis of our eclipse curves allows us to draw the following conclusions
The times of minima in di erent colours in the same cycle coincide within the
errors of their determination The small di erences b etween the times of the minima in
di erent colors when observed simultaneously show that the minima o ccur in a sequence
U B and V except for cycle
The mean phase of our observations relative to the Mandel s yr cycle Nather
Robinson is
J D Hel
d
Then it turns out that our mean O C residual value : marked as a diamond
in Figure falls just on the p erio dic curve adapted from Quigley Africano i e
our observational data supp ort yr cycle of UX UMa
d
In this observational season we obtain the mean orbital p erio d of : This
value is very near to that of Mandel and Kukarkin
The shap e of the eclipse curves in the same colours changes from cycle to cycle
Usually the b ottom of the eclipse is almost symmetric with resp ect to the light minimum
but in some cases its rising branch is deformed Similar p eculiarities were seen by Warner
Nather
The mean duration of the whole minima in di erent colours is ab out minutes
and the mean duration of the stillstand on the ascending branch of the eclipse is ab out
minutes
Figure O C residuals according to Mandel s yr cycle
m m
The mean depth of minima in di erent colours is resp ectively V B :
m
U :
A small stillstand is visible on the descending branch of the eclipse nearly symmet
rically to the one on the ascending branch It is most apparent in the cycles and
This feature is more clearly visible in B than in V
Acknowledgements This work was partially supp orted by a grant from Bulgar
ian National Science Foundation The authors are grateful to the Krakow Pedagogical
University for the telescop e time and to Dr G Pa jdosz for the useful discussion
Diana P KJURKCHIEVA
Dragomir V MARCHEV
Shoumen University
Shoumen
Bulgaria
References
Kreiner J et al IAU Col l No Poster Papers on Stel lar Photometry ed I
Elliott and C Butler Dublin Institute for Advanced Studies p
Kukarkin B MNRAS P
Mandel O Perem Zvezdy
Nather E Robinson E ApJ
Quigley R Africano J PASP
Warner B Nather R MNRAS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
KY Ara IS MISIDENTIFIED
KY Ara was discovered by E Boyce Shapley et al and was classi ed as a
p ossible dwarf nova Finder charts app ear in Tsesevitch Kazanasmas Wycko
and Wehinger and Duerb eck with the later two b eing based on the
pap er This nder chart is based on examination of the original Harvard plates
Tsesevits Kazanasmas
Only one outburst has b een seen in early July JD and this was
on four unidenti ed plates in the Harvard archival plate collection Shapley et al
This single eruption was selected from a search through the GCVS as a candidate for b eing
an event similar to those exp ected from gravitational lensing by a foreground MACHO
star Such events must b e color neutral time symmetric and unique We lo oked into the
case of KY Ara to see if the eruption could b e a MACHO event
Photometry of the star identi ed by Duerb eck was p erformed at the Cerro
Tololo Inter American Observatory on July The brightness of this star was
measured with various standard lters as U B V R and
I with uncertainties of roughly magnitudes These are the normal colors of a
G main sequence star not those of a dwarf nova
Table
Plate JD Comments on brightness of KY Ara
A KY Ara invisible G star visible
A KY Ara invisible G star visible p o or plate
A KY Ara invisible G star visible
MF KY Ara invisible G star visible
MF KY Ara invisible G star visible
MF KY Ara invisible G star visible
A Discovery plate B KY Ara is to east of G star
B Poor plate limit consistent with plate A
A KY Ara slightly brighter than G star B
MF Neither KY Ara nor G star visible
A KY Ara roughly equal to G star in brightness
A KY Ara roughly equal to G star in brightness
MF Neither KY Ara nor G visible p o or plate limit
MF KY Ara invisible G star visible
A Neither KY Ara nor G star visible
A KY Ara invisible G star visible
MF KY Ara invisible G star visible
We then examined the original records and plates at Harvard Table summarizes the
relevant plates The discovery plate was A wich displayed a well formed signi cant
image of KY Ara The other three plates with images of KY Ara are A A
and A although the variable is close to the plate limit in all three cases The
existence of four go o d images at the same lo cation over a six day p erio d convinces us that
KY Ara is indeed a true variable star
KY Ara is identi ed in the original notes of E Boyce as the following star of a double
Examination of plate A shows this to b e true with the preceding star b eing the G
star mistakenly identi ed in later nder charts The origin of this mistake arises from the
chart of Tsesevich Kazanasmas which correctly depicts the discovery plate yet
has the circle centered on the preceding star Subsequent nder charts merely followed
this rst chart
Terry Girard Yale University made PDS astrometric scans of plates A A
and the ESO sky survey plate These con rm that the preceding star is the G star KY
Ara is found to b e roughly magnitude brighter than the G star or B on the
00 00
discovery plate The p osition of KY Ara is : east and : south of the G star With
the p osition of the G star rep orted by Wycko and Wehinger the co ordinates
h m s 00
for KY Ara are : : Examination of the sky survey plates shows
this p osition to b e empty to b elow B magnitude Examination of our CCD images
from Cerro Tololo show the p osition to b e empty to b elow B magnitude Thus the
amplitude of KY Ara is greater than approximately magnitudes
The true nature of KY Ara is unclear The amplitude duration and singularity of
the event are consistent with the Boyce s suggestion of a dwarf nova with a large
amplitude and rare outbursts Alternatively since there is only one observed maximum
KY Ara could b e a fast nova or even a large amplitude MACHO event
Bradley E SCHAEFER
Dorrit HOFFLEIT
Departments of Physics and
Astronomy
Yale University
New Haven Connecticut
USA
References
Duerb eck H Space Sci Rev
Shapley H Boyce E H and Boyd C D Harvard Annals
Tsesevich V P and Kazanasmas M S Atlas of Finding Charts of Variable Stars
Moscow Acad Sci USSR
Wycko S and Wehinger P A Publ Astron Soc Paci c
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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December
HU ISSN
GENEVA PHOTOMETRY OF THE ECLIPSING BINARY TV Nor
The eclipsing binary HD TV Nor has b een brought to the attention of sp ec
troscopists by Renson b ecause it has b een classi ed Ap EuCrSr by Houk
Indeed there is as yet no clear cut case of an Ap star of the Si or SrCrEu type b elong
ing to an eclipsing system This is probably b ecause of the lack of short p erio d binaries
among this kind of p eculiar stars see e g Gerbaldi et al However such a system
would b e most interesting b ecause it is known that the abundance anomalies are not
evenly distributed on the surface of the star but are concentrated into patches follow
ing the large scale magnetic structure Many Ap stars are therefore sp ectrum variables
simply b ecause their rotation brings these patches into view and away from it the art of
Doppler imaging exploits the resulting line variations to map the abundance anomalies
on the surface of the star Such maps however present ambiguities esp ecially regarding
the latitudes of the patches Observing an Ap star undergoing an eclipse by a normal
constant companion would help to remove the ambiguities and even to build an indep en
dant map of the eclipsed hemisphere for the corresp onding rotational phase Piskunov
Rice Vincent et al
In the hop e that HD could b e such a rare system we monitored it with Geneva
photometry in order to obtain a go o d quality lightcurve All measurements have b een
made from the Europ ean Southern Observatory La Silla Chile with the double b eam
P photometer attached to the m Swiss telescop e The rst three routine mea
surements were made as early as and resp ectively and additional
measurements were made in April by the late Dr Zdenek Kviz Systematic moni
toring b egan essentially in June stimulated by Renson s IBVS note and continued
each following season until July
We exp ected that this well detached system would present p erio dic variations outside
the eclipses due to the intrinsic variations of the Ap comp onent The result is however
disapp ointing from this p oint of view as shown in Figure which displays the U B
B V and V curves Outside the eclipses the r m s standard deviations are resp ectively
and which can b e entirely attributed to measurement uncertainties
Thus neither the primary nor the secondary is photometrically variable in a signi cant
way making any sp ectral variation rather improbable
It is interesting to notice that the minima have di erent depths in V and vary in
opp osite ways in B V while U B remains constant This means that the comp onents
have signi cantly di erent e ective temp eratures and sp ectral types The primary is
probably an early or mid A dwarf while the secondary may b e an A or F giant
This fact is probably signi cant regarding the Ap classi cation the sp ectrum app ears
comp osite and was very likely misinterpreted as that of a single Ap EuCrSr star
Figure Geneva U B B V and V lightcurves of the eclipsing binary TV Nor
folded according to the p erio d of Hertzsprung Notice the lack of variability b etween the eclipses
This is con rmed by the b ehaviour of the p eculiarity parameter V G as a function
of phase while this parameter is generally p ositive for Ap stars see e g Hauck North
it remains here at the constant value
V G
with an r m s residual scatter of only magnitudes There is no signi cant variation
at all during the eclipses Therefore the V G value of not only the whole system
but also of each comp onent of TV Nor is quite typical of normal stars
Furthermore one of us PN has taken a sp ectrum of this system with the m CAT
telescop e of the Europ ean Southern Observatory equipp ed with the CES sp ectrograph
the Long Camera and the FA CCD detector ESO CCD The resolving p ower
was R The sp ectrum was taken in the H region on the night of May
at HJD i e at phase according to the ephemeris given in
Figure This is practically at a quadrature and allows us to estimate the total mass of the
system from the relative velocity at that phase and from the Kepler s third law Fitting
a gaussian to the core of the H line of each comp onent we obtain A
p
and A implying a relative velocity V km s If the orbit is
s r
circular which is very probably the case since the eclipses have the same duration and
are separated by exactly half a p erio d and if the inclination i of the orbital plane is close to
o
as the very existence of deep eclipses suggests then we obtain for the semi ma jor axis
Figure High resolution sp ectrum of TV Nor taken at orbital phase
i e at quadrature and showing the star as a double lined system
a AU
and for the total mass
M M M
p s
which is quite consistent with the sp ectral types and luminosity classes prop osed ab ove
for the two comp onents
This binary may well b e sp ectroscopically normal which would designate it as a very
go o d candidate for precise mass and radius determination
Acknowledgements This work was supp orted in part by the Fonds National de la
Recherche Scienti que Drs Z Kviz P Lamp ens and Mrs C Nitschelm and F Barblan
contributed to the photometric observations which were reduced by Mr C Richard
P NORTH
Institut d Astronomie de l Universit e
de Lausanne
CH Chavannes des Bois
Switzerland
M BURNET
Observatoire de Gen eve
CH Sauverny Switzerland
References
Gerbaldi M Flo quet M Hauck B A A
Hauck B North P A A
Hertzsprung E Bul l Astr Netherlands
Houk N Michigan Catalogue of two dimensional spectral Types for the HD Stars
Vol
Piskunov N E Rice J B PASP
Renson P IBVS No
Vincent A Piskunov N E Tuominen I A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
TEN NEW VARIABLE STARS IN HERCULES AND CORONA BOREALIS
Ten new variables were discovered using the p ositive negative metho d in a eld
h m
centered on Her
Our study was based on Moscow collection plates taken with the cm astrograph in
Crimea
Table contains co ordinates and GSC identi cations of new variables for GSC stars
the co ordinates are taken from GSC Table presents for each star number of obser
vations and time interval covered n and JD maximum and minimum brightness B
band type of variability and light elements Magnitudes of comparison stars presented
in Table were obtained using a standard near M Arp and Johnson with im
proved photometry from Forbes and Dawson Finding charts and light curves of
the p erio dic variables are presented in Figures and resp ectively
Sincere thanks are due to S Yu Shugarov for the software used for p erio d determina
tions This study was partially supp orted by the Russian Foundation for Fundamental
Research through grant No
Table
Star GSC
h m s
Var
Var
Var
Var
Var
Var
Var
Var
Var
Var
Remarks for individual stars
Var Period varies The data from JD to are used in Fig for Var
Seven latest observations are not represented with the elements
l b con rming the suggested CWA classi cation
Var Blazhko e ect
Var Red on Palomar charts Fragments of the light curve are given in Fig A
brightness decrease during JD resembles an eclipse
p
Var A secondary minimum exists D Primary minima
JD
Figure
Figure
Table
Star n JD Type B B Light elements
pg M AX pg M I N
m m d
Var RRab : : JD : E
M AX
d
Var RRab JD : E
M AX
d
Var RRab JD : E
M AX
d
Var CWA JD : E
M AX
d
Var RRab JD : E
M AX
d
Var RRab JD : E
M AX
d
Var RRab JD : E
M AX
d
Var RRab JD : E
M AX
Var
d
Var EA JD : E
MIN
S V ANTIPIN
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
References
Arp H C and Johnson H L ApJ
Forbes D and Dawson P C PASP
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
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December
HU ISSN
PHOTOELECTRIC OBSERVATIONS AND MINIMA TIMES OF FOUR
1
W UMa SYSTEMS LS Del SW Lac V Oph AND AQ Psc
During the Summer School of Young Astronomers held at Ankara University Obser
vatory b etween Aug Sept four W UMa systems LS Del SW Lac V
Oph and AQ Psc were observed in B and V lters using a single channel unrefrigerated
SSP photometer attached to the cm Maksutov telescop e The observations were
carried out by the participant students six groups in turn and some colleagues of the
Ankara University Observatory as part of the Summer School program The school was
sp onsored by The Ankara University Science Faculty The Ankara University Graduate
School of Natural and Applied Sciences The Technical and Research Council and The
Turkish Astronomical So ciety
The identi cation and general prop erties of program stars are listed in Table where
Sp No T and P stand for the sp ectral type of the system number of observations ob
tained in each lter ep o ch and orbital p erio d used in phase calculation Each observation
comprises three ve second integrations through B or V lter in sequence comparison sky
variable sky variable comparison sky with o ccasional interruptions for background and
check star measurements Typical r m s error of a single observation is around
mag The control of the photometer head data acquisition and data reduction for atmo
spheric extinction and helio centric correction were carried out with a software prepared
by M uyessero glu The light and color curves of the program stars by using the light
elements from Table are shown in Figures and Part of the scatter in observations
see gures is due to night to night light variations The observations of AQ Psc cover
only the phase interval around secondary minimum
Table Identi cation and general prop erties of the program stars
LS Del SW Lac V Oph AQ Psc
Var Star BD BD BD BD
Comp Star BD BD BD BD
Check Star BD BD BD BD
Sp G G V G V F V F V
No
T
P
Reference Demircan Pena et al Niarchos Sarma and
et al Radhakrishnan
1 Paper dedicated to research assistant H D undarwho died after ulcer op eration on of September
Figure Figure
Figure
Table Times of minima
LS Del SW Lac V Oph AQ Psc
BII BII BI BII
VII VII VI VII
BI BII
VI VII
BII BII
VII VII
From these new observations new times of minimum light were calculated by using
the metho d of Kwee and Woerden The times of minimum light for the asymmetric
eclipse curves of SW Lac were checked by using the well known graphical chord metho d
The resulting new times of minimum light together with their r m s errors are listed in
Table for each system
O Demircan Z Aslan C Ibano glu Z M uyessero glu S O Selam
M Tanriver H Ak H D undar B Albayrak K Y uce
A Devlen A G ok ce H Cal skan A Iskender Y Kaya
A Bulut E C nar H Varl N Cubukcu K Ulu c
A Savranlar G Sen H Ozdemir O Cak rl M Da gc
Y Y uksel G Ta s Y Alemdar R T Y ld r m Y Erdal
A A s cilar E A c kg oz B Bekta sli F G oksen N K oker
Ankara University Observatory
Faculty of Science
TR Tandogan Ankara
Turkey
References
Demircan O Selam S O and Derman E Ap SS
Kwee K K and van Woerden H Bul l Astr Neth
M uyessero glu Z Ankara Univ Obs unpublished
Niarchos P G Ap SS
Pena J H Hobart M A and Ro driguez E it Rev Mex A Ap
Sarma M B K and Radhakrishnan K R IBVS No
COMMISSIONS AND OF THE IAU
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Number
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December
HU ISSN
BVRI PHOTOMETRY OF CG CYGNI
CG Cygni BD in the catalog of Strassmeier et al is a
member of the short p erio d eclipsing RS CVn class of stars Budding and Zeilik
rst mo deled the sp ots on this star Zeilik et al mo del the sp ot structure for
available data from to and review the literature on this star
I observed CG Cyg on the nights of and August using the
San Diego State University cm telescop e on Mt Laguna The telescop e is equipp ed
with a photometer using a Hamamatsu R tub e op erated at V and co oled to
The BVRI lters are chosen to closely match the Johnson Cousins system I used
BD SAO as a comparison star The data plotted in Figures and
are di erential magnitudes star comparison in the standard Johnson Cousins system
Zeilik et al discuss small amplitude variations outside the eclipses that are seen by
several di erent indep endent observers These variations are apparent in the data
but their nature is still uncertain
I mo deled the data using the Information Limit Optimization Technique ILOT de
scrib ed in detail by Budding and Zeilik I extracted a distortion wave from the
initial binary star t then t the distortion wave for the longitude and radius of two K
circular sp ots at a xed latitude Figures and show these ts for the B band The
ts for each wavelength are p erformed indep endently I get
B band V band R band I band
Longitude
Latitude
Radius
Longitude
Latitude
Radius
2
Note that the mo dels in the di erent bands agree to within the errors Zeilik et al
nd that the sp ots for CG Cyg tend to cluster in Active Longitude Belts at and
These mo dels show the same phenomenon
Figure Figure
Figure Figure
After p erforming the sp ot ts the e ects of the distortion wave were removed and
clean ts were made to the corrected light curve I get
2
L k r r r i L q M M
1 2 1 1 2 2 1
B
V xed
R xed
I xed
The values of L k r i and L all agree with the values found by Zeilik et al
1 1 2
I was only able to simultaneously t the inclination and mass ratio in the B band In
the other bands I xed the inclination to try to get some information on the mass ratio
b ecause the results of Zeilik et al give a go o d value for the inclination Most
previous values of the mass ratio are Naftilan and Milone Sowell et al
Jassur gets and Popper gets The values ab ove are derived from
only photometric data at one ep o ch and are therefore less reliable than values derived
using sp ectroscopic data However these values lend credence to the lower value of the
mass ratio found by Popper
Because I was unable to observe an entire primary or secondary eclipse on a single
night I am not able to give a reliable observed time for either the primary or secondary
eclipse However the ILOT program makes a b est t correction to the phase of primary
minimum From that information averaged over the observed wavelengths I nd that
the eclipses are observed days b efore they are computed to o ccur during
this ep o ch
I thank Ron Angione for scheduling generous amounts of observing time at Mt Laguna
and the Research Corp oration for providing generous nancial supp ort
P A HECKERT
Dept of Chem Physics
Western Carolina University
Cullowhee NC USA
References
Budding E and Zeilik M Astrophys J
Jassur D M Z Ap Space Sci
Naftilan S A and Milone E F Astron J
Popper D M Astrophys J L
Sowell J R Wilson J W Hall D S and Peyman P E Pub Astron Soc
Pac
Strassmeier K et al Astron Astrophys Suppl
Zeilik M Gordon S Jaderlund E Ledlow M Summers D L Heckert P A
Budding E and Banks T S Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
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December
HU ISSN
B AND V PHOTOELECTRIC OBSERVATIONS
OF THE CONTACT BINARY XY Leo
XY Leo is a short p erio d contact binary with multiple CaI I H and K emission lines
and strong X ray emission Hrivnak et al Vilhu and Rucinski The O C
diagram has a sine like shap e but sudden changes of p erio d of XY Leo were observed
three times Gehlich et al These phenomena were explained sucessfully by BY
Dra type activity of the other pair of stars in the system Barden The variations
in the light curves of the binary were detected as usually for all W systems
Our observations of XY Leo were carried out on three nights and November
The four channel WBVR photometer attached to the cm re ector was used
Kornilov and Krylov The observations were made at High Altitude Alma Ata
Observatory of Sternberg Astronomical Institute BD served as the comparison
m m
star The mean error of magnitudes range from : to : in each lter These values
are due to small ratio of signal to noise for stars of such brightness V and B light
curves of XY Leo are presented in Figure Phases are calculated by the ephemeris from
Krzesinski et al
d
MinI J D hel : E
The observations allowed us to determine the times of one primary and two secondary
minima by graphical metho d separately for each colour Table I contains the moments of
minima type of minima and O C values as calculated from the same ephemeris Figure
Table I
JD Min Filter O C
hel
II V
II B
I V
I B
II V
II B
L T MARKOVA
Lab oratory of Astrophotometry
and Stellar Atmospheres
G V ZHUKOV
Department of Astronomy
Kazan University
Lenina Kazan
Russia
E mail gera astro kazan su
References
Barden S C Astrophys J
Gehlich U K Prolss J Wehmeyer R Astron Astrophys
Hrivnak B J Milone E F Hill G Fisher W A Ap J
Kornilov V G Krylov A V Soviet Astronomy
Krzesinski J Kuczawska E Kurpinska Winiarska M IBVS No
Vilhu O Rucinski S M Astron Astrophys
COMMISSIONS AND OF THE IAU
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December
HU ISSN
THE IDENTIFICATION OF VARIABLE STARS
DISCOVERED WITH THE HUBBLE SPACE TELESCOPE
IN THE GLOBULAR CLUSTER MESSIER
Recently Guhathakurta et al published a list of variable stars detected in
the core of the globular cluster M using HST images The stars have relative astrometric
p ositions In another list by Evstigneeva et al accurate astrometric p ositions are
given for all known variable stars in this cluster except ob jects which the authors could
not identify The examination of these lists shows that they contain common ob jects I
have reduced the relative p ositions by Guhathakurta et al to equatorial co ordinates in
the system by Evstigneeva et al using common ob jects The agreement b etween the
00
p ositions is very go o d the r m s deviation b eing :
As a result variables were identi ed with ones from the list by Sawyer Hogg
two variables b eing close comp onents of one earlier known variable V V a
variable lost by Evstigneeva et al was identi ed with ID using a chart by Kholop ov
variables were discovered earlier by Kholop ov and variables by Kadla
and Gerashchenko
The identi cations are given in the Table Two identi cations ID with V and
ID with X are marginal b ecause their p ositions measured with a ground based
telescop e may b e not accurate So variables may b e new discoveries with the HST
The equatorial co ordinates are those reduced from relative astrometry by Guhathakurta
et al
V P GORANSKIJ
Sternberg Astronomical Institute
Universitetskij Prosp ekt
Moscow Russia
References
Evstigneeva N M Samus N N Tsvetkova T M and Shokin Yu A Pis ma v
Astron Zhurn Russian Astronomy Letters No
Guhathakurta P Yanny B Bahcall J N and Schneider D P Astron J
No
Kadla Z I and Gerashchenko A N Astron Circ Russia No
Kholop ov P N Variable Stars No
Sawyer Hogg H David Dunlap Obs Publ No
ID No Desig RA Decl Deviation Remarks
h m s 0 00 00
V : : :
V
V n
V s
V
X
V
new
V
X
new from X
V
V
V
X
new SX Phe type var
V
X
new from V
new
V
V
V
V
X
new from X
V
new SX Phe type var
new
KG
KG
V
V Cepheid
new
new
V
new Var RGB star
KG
X
V
Catalogues V Sawyer Hogg X Kholop ov KG Kadla and Gerashchen ko
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HU ISSN
SPECTROSCOPIC BINARITY OF THE CEPHEID BY Cas
The variability of BY Cas was discovered by Beljawsky According to Szabados
this s type Cepheid shows considerable p erio d variability and after JD
d
varies with the p erio d
Joy published radial velocity values for BY Cas one radial velocity measure
ment was later published by Rastorgouev et al Szabados was not able to
derive velocity for this star Usenko suggested the presence of a B companion
from the star s p osition in the two color diagram In our catalog Gorynya et al
of Cepheid radial velocities measured with the CORAVEL type sp ectrometer designed
by Tokovinin we presented velocities of the star and susp ected variability of its
velocity
We have now added new measurements of the radial velocity of BY Cas These results
clearly con rm that the star is a sp ectroscopic binary Though the radial velocity data
are still not very abundant we have attempted to determine provisional orbital elements
Several sets of orbital elements still remain p ossible but presently we prefer the solution
d d
with small eccentricity T P e
or b
km s K km s
Table
JD V km s Phase Phase V V
hel r r r
hel km s orbit puls orbit puls
Table presents available correlation sp ectrometer radial velocities of BY Cas as well
as the Cepheid s velocities separated into an orbital and a pulsational term The columns
contain helio centric Julian dates measured helio centric radial velocities their internal
r m s errors phases of the orbital cycle calculated with our provisional elements phases
of the pulsational cycle calculated using improved light elements in the time interval JD
hel
d
M ax E
hel
orbital motion comp onents of the radial velocity computed from the orbital elements
radial velocity residuals to b e attributed to pulsations
Thanks are due to Dr A Tokovinin for providing p ossibility to use his sp ectrometer
and to Sternberg Institute observers and students who to ok part in observations according
to our program
N A GORYNYA
N N SAMUS
Institute of Astronomy
of Russian Academy of Sciences
Pyatnitskaya Str
Moscow Russia
A S RASTORGOUEV
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
References
Beljawsky S Astron Nachr
Gorynya N A Irsmambetova T R Rastorgouev A S Samus N N Sov Astron
Letters
Joy A H Astrophys J
Rastorgouev A S Valitova A M Glushkova E V Kulagin Ju V Pavlov M V Samus
N N in Catalog of Measured Stel lar Radial Velocities Catalog of Proper Mo
tions Tokovinin A A ed Moscow Moscow University Press p
Szabados L Budapest Mitt Nr
Tokovinin A A Soviet Astronomy
Usenko I A Kinem Fiz Neb Tel English translation in Kinem Phys
Celest Bo dies No
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December
HU ISSN
WW CEPHEI ELEMENTS REDISCOVERED AND IMPROVED
BAV Mitteilungen Nr
The Algol type eclipsing binary WW Cep Cephei was discovered by Schnel
ler on photographic plates of Bab elsb erg Observatory Later Schneller
m m
published a list of individual photographic magnitudes ranging b etween and
h
determined the time b etween rst and last contact of the primary minimum as D
and rep orted the following rst elements
d
Min I HJD : : E:
Metzger rediscovered the variable indep endently on the same photographic plates and
d d
found D and d Staker WW Cep was again investigated by G otz
on plates of the Sonneb erg Sky Survey He submitted four minima timings and
calculated new elements
d
Min I HJD : : E:
With these elements WW Cep is listed in the GCVS Silh an rep orted
that in a photographic and visual search the primary minimum could not b e found Lacy
noted that his sp ectrograms are inconsistent with the ephemeris listed in the GCVS
Photo electric photometry by Lacy showed no sign of an eclipse at phase
Using the photographic magnitudes published by Schneller together with
the elements from the GCVS a reduction to one cycle shows that seven measurements
contradict the ephemeris used In spite of all that two BBSAG observers published
visual minima which follow quite well the published elements These discrepancies made
WW Cep a candidate for the observing program of the author
The observations were made at his private observatory with an SBIG ST CCD camera
without lters attached to a cm SC telescop e WW Cep was observed on nights
b etween Apr and Oct The rather large scatter in the lightcurve is due to
not always photometric weather conditions The minima times were calculated using
the Kwee van Woerden metho d From ab out two and a half thousand pictures
over almost all phases the true p erio d could b e rediscovered It is very near the original
one suggested by Schneller In the instrumental system the depth of the primary and
m m
secondary minima were found to b e and resp ectively
Using the minima from Parenago and Schneller together with the new observations
a least squares t yields the following linear ephemeris The visual observations by the
BBSAG seem to b e a ected by systematic error and had to b e excluded
d
Min I HJD : : E
Figure Di erential light curve of WW Cep computed
with resp ect to the new ephemeris
Figure O C diagram for WW Cep computed with resp ect to
the new ephemeris using all available minima timings
represents photo electric photographic series
visual observations and photographic plate minima
2
Figure O C diagram for WW Cep computed with resp ect to
the new ephemeris using only photo electric observations
Table Observed times of minima for WW Cep ep o chs and residuals
computed with resp ect to the ephemeris derived in this pap er
N JD hel W T Ep o ch O C Lit N JD hel W T Ep o ch O C Lit
P V
V P
F V
P V
V P
P V
P V
P V
E P
P V
E V
V E
V E
E V
V E
V E
V E
E V
E V
Parenago Schneller G otz Peter Peter Peter
Peter a Bl attler Peter b Bl attler Peter Peter
Peter Peter a Peter b Peter this pap er
P denotes pg plate min E CCD min F pg series and V visual estimates Those marked with got reduced weight
while those marked with were discarded
It should b e mentioned that plate E at ep o ch m of the list of
photographic magnitudes by Schneller if signi cant seems to indicate the descend
to a secondary minimum If this is true the phase of min II would have b een at phase
whereas the new measurements show min I I at phase Therefore WW Cep may
b e a system with apsidal motion
F AGERER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Zweikirchen Dorfstrasse
D Tiefenbach Germany
References
Bl attler E BBSAG Bul l
Bl attler E BBSAG Bul l
G otz W Mitt Ver Sterne
th
Kholop ov P N et al Gen Cat of Var Stars Ed Nauka Moscow
Kwee K K van Woerden H Bul l Astr Inst Netherlands
Lacy C H Inf Bul l Var Stars No
Lacy C H Astr Journal
Parenago P Perem Zvezdy
Peter H BBSAG Bul l
Peter H BBSAG Bul l
Peter H BBSAG Bul l
Peter H a BBSAG Bul l
Peter H b BBSAG Bul l
Peter H BBSAG Bul l
Peter H BBSAG Bul l
Peter H BBSAG Bul l
Peter H a BBSAG Bul l
Peter H b BBSAG Bul l
Peter H BBSAG Bul l
Schneller H Astr Nachrichten No
Schneller H Ver Berlin Babelsberg
Silh an J Contr N Copernicus Obs and Plan Brno
Staker P Astr Nachrichten No
COMMISSIONS AND OF THE IAU
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December
HU ISSN
V LYRAE NEW EPHEMERIS AND LIGHTCURVE
BAV Mitteilungen Nr
In this pap er we rep ort on our photographic and CCD photometry on the Lyr type
variable V Lyr
V Lyr SVS CSV was announced as a short p erio d variable by
m m
Parenago with a brightness range b etween and Meinunger
investigated this variable on plates of the Sonneb erg Sky Survey He classi ed the star as
eclipsing gave minima calculated from them a rst ephemeris as
d
Min I HJD E
and published a rst photographic light curve The range in this lightcurve is roughly
m m th
b etween and The variable got its de nitive name in the name list of
variable stars Kukarkin et al With the data ab ove V Lyr was included in the
fourth edition of the GCVS Kholop ov et al
For more than twenty years the variable had remained obviously unobserved when
the BAV published a photographic minimum timing Moschner Kleikamp Since
that time we have investigated V Lyr photographically and photo electrically The
photographic observations were made with a cm RC telescop e and the exp osures were
evaluated with a xed diaphragm photometer The CCD observations were p erformed
with an SBIG ST camera without lters attached to a cm SC telescop e F A or to the
cm RC telescop e W M Altogether three new photographic and nine CCD minima
could b e collected All minima times were calculated with the Kwee van Woerden
metho d In the instrumental system of the CCD observations the depth of the primary
m m
and secondary minima were found to b e and ab out resp ectively In compiling
the lightcurve Figure from our data it b ecame evident that the p erio d published in
the GCVS was a spurious one with the relation
P P
GCVS
Using all published minima found in the BAV Database of Minima of Eclipsing Bina
ries together with our new observations a weighted least squares t yields the following
linear ephemeris
d
Min I HJD E
Figure Di erential lightcurve of V Lyr
computed with resp ect to the new ephemeris
Figure O C diagram for V Lyr computed with resp ect to
the new ephemeris using all available minimum timings
represents photo electric photographic
series and photographic plate minima 2
Table Observed times of minima for V Lyr ep o chs and residuals
computed with resp ect to the ephemeris derived in this pap er
N JD hel W T Ep o ch O C Lit N JD hel W T Ep o ch O C Lit
P P
P P
P P
P P
P P
P P
P P
P P
F P
F P
F P
P F
P E
P E
E P
E P
P E
E P
P E
E P
E P
Parenago Meinunger Moschner Kleikamp Moschner Kleikamp this pap er
Agerer this pap er Moschner this pap er
P denotes pg plate min E CCD min and F photographic series Those marked with got reduced weight
F AGERER
W KLEIKAMP
W MOSCHNER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm
D Berlin Germany
References
Meinunger L Mitt Ver Sterne
Moschner W Kleikamp W BAV Mitteilungen Nr
th
Kholop ov P N et al Gen Cat of Var Stars Ed Nauka Moscow
th
Kukarkin B V et al name list of variable stars IBVS No
Kwee K K van Woerden H Bul l Astr Inst Netherlands
Parenago P Perem Zvezdy
COMMISSIONS AND OF THE IAU
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December
HU ISSN
PHOTOMETRIC OBSERVATION OF V CYGNI
BAV Mitteilungen Nr
m
V Cyg was discovered by Mayer as a variable of EA type with and
m
deep primary and secondary minima resp ectively He submitted three moments of
minima and gave a rst ephemeris as
d
Min I HJD : : E:
With the ab ove data V Cyg is listed in the fourth edition of the GCVS Kholop ov
m m
et al as to b e variable b etween : and :
The variable had remained obviously unobserved for ab out years when the BAV
published two times of minima Agerer Together with V Cyg which is in the
same eld of our CCD camera this variable was further investigated In contradiction
to the ephemeris ab ove an observing run on Aug shows a minimum of V Cyg
Two additional minima at times when the variable was exp ected to b e constant together
with observations b etween minima proved that the p erio d listed in the GCVS has to b e
divided by ve
Using all minima times available from the BAV Database for Minima of Eclipsing
Binaries by D Lichtenknecker a least squares t yields the following linear elements
d
Min I HJD : : E
Figure CCD image of V Cyg a and V Cyg b
Figure O C diagram for V Cyg computed with resp ect
to the new ephemeris using all available minima timings
Table Observed times of minima for V Cyg ep o chs and residuals
computed with resp ect to the ephemeris derived in this pap er
N JD hel W T Ep o ch O C Lit N JD hel W T Ep o ch O C Lit
E E
E E
E E
E E
E
Mayer Agerer Agerer this pap er
F AGERER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Zweikirchen Dorfstrasse
D Tiefenbach Germany
References
Agerer F BAV Mitteilungen
th
Kholop ov P N et al Gen Cat of Var Stars Ed Nauka Moscow
Mayer P Bul l Astron Inst Czechoslovakia
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
VW CANUM VENATICORUM NEW EPHEMERIS AND LIGHTCURVE
BAV Mitteilungen Nr
In this pap er we rep ort on our photographic and CCD photometry on the RR Lyr type
variable VW CVn
VW CVn SVS was discovered by Kuro chkin as variable of W UMa or
m m
Lyr type with a range of brightness b etween and Kuro chkin calculated two
sets of rst elements and gave rst photographic light curves Elements valid after JD
were
d
Min I HJD E
With the ab ove data VW CVn is listed in the fourth edition of the GCVS Kholop ov et
al Until recently the variable remained almost unobserved exceptions Diethelm
Diethelm and German when Vandenbroere found the elements
to b e in error This prompted us to put VW CVn on our observing program
One of us T B investigated this variable on plates of the Sonneb erg Sky Survey
The observations by the other were made with an SBIG ST camera without lters
attached to a cm SC telescop e From these measurements we found the variable to b e
m m
of RR Lyr type the range of brightness is b etween and pg and M m
Analysing the CCD measurements we got rst elements
d
Min I HJD E
The timespan covered by the Sonneb erg plates was divided into several
parts Using this rst ephemeris for each of these parts a mean lightcurve was cal
culated and the time of the normal maximum was derived see Table Obviously the
p erio d did not remain constant in the time interval studied Considering the accuracy
of estimates on photographic plates the p erio d probably changed ab out ep o ch number
Least squares ts in each of these intervals yield the following linear elements
d
Min I HJD E
valid b etween JD and JD
d
E Min I HJD
valid after JD
Figure Mean light curve from all photographic estimates of VW CVn
on plates of the Sonneb erg Sky Survey computed with resp ect to the
new ephemeris Magnitudes according to Kuro chkin The hump near the
maximum is a result of very bright observations app earing only temp orarily
in exactly that range of phase
Figure Di erential CCD light curve of VW CVn computed with resp ect to the
new ephemeris Each p oint is the result of one CCD image
Figure O C diagram for VW CVn computed with resp ect to the
new ephemeris using all available maximum timings
represents photo electric photographic normal maxima
Times of normal maxima for VW CVn ep o chs and residuals
computed with resp ect to the ephemeris derived in this pap er
N JD hel W T Ep o ch O C Observer
P T Berthold
P
P
P
P
P
P
P
P
P
E F Agerer
P denotes photographic normal maxima
E CCD observed normal maximum
A detailed pap er dealing with further analysis of the long time b ehaviour of the p erio d
and the results of the CCD photometry is now in progress
F AGERER
T BERTHOLD
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm
D Berlin Germany
References
Diethelm R BBSAG Bul l
Diethelm R BBSAG Bul l
German R BBSAG Bul l
th
Kholop ov P N et al Gen Cat of Var Stars Ed Nauka Moscow
Kuro chkin N E Perem Zvezdy
Vandenbroere J BBSAG Bul l
ERRATUM
In the No issue of the IBVS all ephemerides of VW CVn refer to normal maxima
and not Min I as stated erroneously in the text The authors of that note and editors
of the IBVS are grateful to Dr N Samus for calling their attention to this inconsistency
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
A PRE MAIN SEQUENCE COMPANION TO AR AURIGAE
A recent analysis of the well known bright eclipsing binary AR Aurigae HD
d
HR V B VpHgMn B V P : days suggests that the sec
max AB
ondary star is still contracting towards the ZAMS while the primary star app ears to b e
exactly on the ZAMS Nordstr om Johansen Moreover AR Aur is a triple sys
tem the existence of the as yet unseen third star b eing inferred from a light time e ect
in the observed minima with a p erio d of years Cho chol et al Nordstr om
Johansen
AR Aur A M and B M are of considerable interest as co eval and nearly
equal mass stars apparently just arriving on the ZAMS Given the remaining observational
uncertainties in the absolute dimensions it is of interest to verify this scenario by other
means Direct detection of star C would supp ort this scenario and provide an estimate of
the mass of star C and the inclination b etween the two orbital planes This note discusses
how this test could b e made
Mo dels by Mazzitelli have b een used to estimate the radius R temp erature
C
T and luminosity L for star C at an age of yr the time for star A to reach
C C
the ZAMS from the birthline for di erent assumed values of i the inclination of the long
p erio d orbit the eclipsing pair has i : The results are given in Table Values of
i less than are not listed since the mass of star C M would b e high enough for C
C
to make a detectable contribution at visible wavelengths contrary to what is observed
Assuming black bo dy radiation the luminosity of star C can then b e computed for any
wavelength and normalised to units of L L thus the quantity l third light
A B C
plotted in Figure and given for some standard photometric passbands in Table is l
C
L L L
C A B
Table Mo del prop erties for AR Aur C at an age of years
i M R T l R l I l J l H l K l L l M
C C C C C C C C C C
Figure Fractional light of star C as a function
of assumed orbital inclination and wavelength
If the light contribution from star C is signi cant the depth of the minima in the
light curves of the eclipsing pair AB will b e reduced The question we wish to address is
the following Given the photometric elements radii and inclination from our previous
analysis of light curves of AB at wavelengths where third light is negligible at what
larger wavelength could we observe a reduction in eclipse depth due to star C relative
to what we would predict without it
Using the b A light curve and analysis to ols from our previous study we have
F
studied this question by adding sp eci ed amounts of third light and then redetermining
l from the light curve gradually reducing the number of p oints used We nd that we
C
can recover l rather accurately with a surprisingly few observations of the precision of
C
the b light curve mag Typical standard errors are with p oints with
F
just well distributed p oints on the light curve ab out half near b oth mid eclipses half
outside eclipse This remarkable economy is p ossible b ecause the existing high quality
analysis provides an accurate prediction of the eclipse depths in the absence of third light
The errors in l scale of course with the mean errors of the actual new observations
C
which will also dep end on the wavelength of observation
The dotted line in Figure indicates the usable wavelength for which of third light
is measurable with certainty For inclinations close to i e near co planarity of the
orbits the K band m is just at the detection limit for star C with photometry
In the L and M bands and m detection will b e easier but photometry probably
corresp ondingly more di cult The N band m should b e avoided as dust emission
might b e signi cant
Deviations from the ephemeris derived earlier for the eclipsing pair AB
d
Min I HJD : E
due to motion in the AB C orbit are not more than minutes and secondary minima
o ccur midway b etween primary eclipses since the AB orbit is circular In planning follow
up photometry observers should b e aware of the problems with variable comparison stars
describ ed in Nordstr om Johansen It is prop osed to use two of the reliable stars
HR HR or HR HR has a faint m companion at a distance
V
00
of : which always should b e included
K T JOHANSEN
B NORDSTROM
The Niels Bohr Institute of
Astronomy
Physics and Geophysics
Astronomical Observatory
Brorfeldevej
DK T ll se
Denmark
References
Cho chol D Juza K Mayer O Zverko J Ziznovsky J Bul l Astron Inst Czech
Mazzitelli I in Low Mass Star Formation and Pre Main Sequence Ob jects B
Reipurth ed ESO Conference and Workshop Pro ceedings No p
Nordstr omB Johansen K T IBVS No
Nordstr omB Johansen K T A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
AK CANCRI A NEW LARGE AMPLITUDE
SU UMA TYPE DWARF NOVA
AK Cnc was discovered by Morgenroth who classi ed it as a p ossible short
p erio d variable star After a long p erio d of confusion the ob ject was identi ed as a
dwarf nova for a review see Wenzel The p eculiarity of this ob ject was noted
by Szkody and Howell who identi ed strong Balmer and helium emission lines
and a red continuum in the sp ectrum of AK Cnc and estimated the quiescent M value
V
b etween and The faintness of quiescent M and a large outburst amplitude
V
mag make AK Cnc a go o d candidate for a TOAD Tremendous Outburst Amplitude
Dwarf Nova Howell A search for a photometric p erio d however has remained
unsuccessful Howell et al
On Jan the ob ject was caught in one of its rare outbursts at m
V
Koshiro private communication We obtained a V band CCD photometry of this star
on three nights b etween Jan and Jan The observations were carried out using a
cm re ector and a Thomson TH chip pixels at Ouda Station Department
of Astronomy Kyoto University for a description of the instruments see Ohtani et al
The exp osure time was b etween and s to avoid saturation from the strong
mo onlight The frames were rst corrected for standard de biasing and at elding and
were then pro cessed by a micro computer based automatic ap erture photometry package
developed by the author The di erential magnitudes of the variables were determined
h m s 0 00
using a lo cal standard star C J V whose
h m s 0 00
constancy was con rmed using a check star C J
V Total number of useful frames was
The resulting overall light curve is shown in Figure The zero p oint corresp onds to
V A general trend of slow linear decline is evident Sup erimp osed on this decline
sup erhumps with an amplitude of mag were detected on all nights The star was
thus for the rst time identi ed as b eing an SU UMa type dwarf nova
A representative light curve is shown in Figure a large scatter in the light curve
is caused by a high sky background due to the proximity of the ob ject to the nearly
full mo on A p erio d analysis using the phase disp ersion minimization PDM metho d
Stellingwerf implemented in the IRAF package after removing the steady decline
yielded the b est estimate of the sup erhump p erio d of day A light curve
folded on this p erio d is shown in Figure Each p oint represents an average of phase
bin and its standard error This clearly demonstrates all the characteristics of fully grown
sup erhumps a rather steep rise to maximum slower decline and a broader secondary
maximum around sup erhump phase The sup erhump makes AK Cnc a member
of short orbital p erio d SU UMa type dwarf novae This picture is in go o d agreement with
the sp ectroscopic features describ ed by Szkody and Howell
Figure General V band light curve of AK Cnc
The zero p oint of the relative magnitudes corresp onds to V
Figure Sample light curve Jan
Sup erhumps with an amplitude of mag are clearly seen
Figure Light curve folded on the sup erhump p erio d of day
The outburst characteristics of this dwarf nova is still uncertain Wenzel gives
ve outburst records from Sonneb erg plates The second one in his table March
is clearly a sup eroutburst Further monitoring for outbursts of this dwarf nova is
encouraged in order to determine its true outburst frequency and number ratio of sup er
and normal outbursts b oth of which would also b e go o d indicators for discriminating
TOADs from other dwarf novae
The author is grateful to Masami Koshiro VSOLJ for notifying us of the outburst
Part of this work was supp orted by a Research Fellowship of the Japan So ciety for the
Promotion of Science for Young Scientists
Taichi KATO
Dept of Astronomy Faculty of Sci
Kyoto University
Sakyo ku Kyoto Japan
References
Howell S B in Cataclysmic Variables and Related Physics ed O Regev G Shaviv
Annals of the Israel Physical So ciety Vol p
Howell S B Szkody P Kreidl T J Mason K O and Puchnarewicz E M
Publ Astron Soc Paci c
Morgenroth O Astron Nachricht
Ohtani H Uesugi A Tomita Y Yoshida M Kosugi G Noumaru J Araya S Ohta
K et al Memoirs of the Faculty of Science Kyoto University Series A of
Physics Astrophysics Geophysics and Chemistry
Stellingwerf R F Astrophys J
Szkody P and Howell S B Astrophys J Suppl
Wenzel W IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
POSITIONS OF VARIABLE STARS IN PLAUT S FIELD
This pap er continues the study announced in our previous publication Antipin et al
a and deals with the variable stars in the Palomar Groningen Field Plaut
This eld contains variable stars discovered by Plaut Using photographic nding
charts prepared by L Plaut and available in Moscow we have checked for p ossible GSC
identi cations stars have b een identi ed with the GSC We have also checked stars
discovered in this eld by other authors and identi ed of them with GSC ob jects We
are not able to present the corresp onding table here b ecause of volume restrictions and
are planning to publish this list in Astronomical and Astrophysical Transactions We have
not found very signi cant p ositional mistakes among those stars we were able to identify
with GSC We have also checked p ositions for non GSC variable stars and found quite a
number of serious mistakes in GCVS p ositions The corrected co ordinates presented in
Table Corrected Co ordinates for Variable Stars
Plaut GCVS NSV : :
h m s m s 0
V Sgr : : :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
NSV :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V Sgr :
V CrA :
NSV
NSV :
Table Identi cations of Several GCVS Stars
V Sgr V Sgr Plaut
NSV V Sgr Mayall chart
V Sgr NSV Strohmeier et al
V Sgr V Sgr Rosino
V Sgr V Sgr Rosino
V Sgr V Sgr Plaut
V Sgr V Sgr Plaut
V Sgr V Sgr V Sgr GCVS
Table have b een determined by one of us S A relative to GSC stars The columns
of the table contain Plaut s numbers the two last lines without Plaut s numbers re
fer to variables discovered by Rosino in the eld of the globular cluster NGC
GCVS or NSV designations right ascensions and declinations p ositional
di erences found in the sense GCVS minus present study
Table contains stars for which p ositional inaccuracies have led to multiple entries in
the GCVS and the NSV catalogue The rst column gives Plaut s numbers The second
column presents the existing GCVS or NSV designations The last column of the table
identi es the source of error If the star in Table do es not enter also Table Plaut s
co ordinates for this star are to b e preferred
Several nal remarks deal with di cult cases It turns out that Plaut s variable No
h m s 0
: Cepheid with a p erio d of days according to Plaut
never got a GCVS designation The reasons for this are presently unclear no indication
of any mistakes revealed is present in GCVS team records Though the star could not b e
identi ed with any GSC star Plaut s co ordinates agree with the photograph We have
not b een able to nd Plaut s No V Sgr The photograph do es not agree with
the co ordinates a great mistake in co ordinates is probable
Mr J M anek has turned our attention to a mistake in the second pap er of the
present series Antipin et al b The declination presented there for V Oph
GSC is wrong the correct value is
Thanks are due to Mr Jan M anekfor his attention to our work
N N KIREEVA
S V ANTIPIN
N N SAMUS
Sternberg Astronomical Institute
Institute of Astronomy
of Moscow University
of Russian Academy of Sciences
Universitetskij Prosp
Pyatnitskaya Str
Moscow Russia
Moscow Russia
References
Antipin S V Kireeva N N and Samus N N a Inf Bul l Var Stars No
Antipin S V Kireeva N N and Samus N N b Inf Bul l Var Stars No
Mayall M W Harvard Obs Bul l No
Plaut L Astron and Astrophys Suppl Ser No
Rosino L Asiago Obs Contrib No
Strohmeier W Knigge R and Ott H Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
1
TIMINGS OF SELECTED VARIABLE STARS
Changes in the p erio ds of variable stars can b e determined by timing the o ccurrence
of a certain p oint in the light curve usually the maximum or minimum value It is
necessary to have such timings at frequent enough intervals so that cycle counts can b e
reliably determined in b etween Often in the course of other routine observations such
timings are obtained and the purp ose of this pap er is to make available such data to other
researchers
Most of the photometric data were obtained with telescop es at Lowell Observatory in
Flagsta AZ but some came from CTIO in Chile Sco and Eri The raw photometry
was corrected for sky and the atmospheric extinction was removed using a comparison
star Then di erential magnitudes were determined and helio centric corrections applied
For stars with a single mo de plots of the light curves were made and a cross correlation
technique b etween the ascending and descending branch was used to derive the time
of maximum or minimum The uncertainty of an individual timing varies with data
quality but is typically days It is planned to submit all of the data up on which
these timings have b een made to the Journal of Astronomical Data Twin Press The
Netherlands
Table Times of Photometric Minimum of Eclipsing Binary Stars
Star Name HJD notes
BX And primary min
secondary min
primary min
TY Bo o primary min
secondary min
W Crv primary min
primary min
secondary min
primary min
secondary min
1
Visiting Observer Lowell Observatory Flagsta Arizona USA Also based in part on data collected at Cerro Tololo
Inter American Observatory National Optical Astronomy Observatories op erated by the Asso ciation of Universities for Research in Astronomy Inc under contract with the National Science Foundation
Table Times of Photometric Maximum Minimum of Cephei Stars
Star Name HJD notes
Eri max for P d
max for P d
Sco max for P d
max for P d
BW Vul max
min
max
min
max
max
min
max
min
max
min
min
max
min
max
min
max
min
max
min
max
min
max
Table lists the times of primary and secondary minimum for three close binary stars
There is enough new data only for W Crv to pro duce a new ephemeris at this time For
these close binaries it might b e exp ected that the orbital p erio d might b e changing due
to mass exchange b etween the two stars so b oth a linear and quadratic ephemeris were
computed combining timings for W Crv from the literature with the ve listed in Table
The least squares quadratic ephemeris yielded only marginally smaller residuals than
the linear and in any case pro duced a rate of p erio d change of just seconds century
which is probably only an upp er limit The linear ephemeris can b e used to schedule future
observations it is
HJD E
Table gives times of maximum and minimum brightness for three Cephei stars For
those with multiple mo des cosine functions were t using the known p erio ds but solving
for the b est phase and amplitude of each mo de and the time of maximum was derived
Figure 1: BW Vul - Ephemeris 350
300
250
200
150 (O-C) 100
50
0
-50 35000 40000 45000 50000
HJD 2400000+
Figure O C diagram for BW Vul
These timings are completely indep endent of each other and dep end on the b eat
phase of the star at the time of the observation For BW Vul times of minimum light
are included b ecause of the suggestion by Sterken Young and Furenlid that the
stillstand in this star s light curve could alter the timings derived for maximum brightness
A least squares linear ephemeris was t to all times of maximum brightness measured
for BW Vul since which can b e used for predicting maximum brightness for the near
future
HJD E
with an rms residual of minutes
The p erio d history of BW Vul has b een controversial for ab out ten years since the
discovery of a p erio dic variation of the residuals after a quadratic ephemeris has b een
removed made by Odell The quadratic ephemeris can b e explained in terms of
the star s evolution to larger size and the p erio dic residuals can b e explained either by
the light travel time over a binary orbit or by two mo des b eating with a p erio d of ab out
years The controversy arises from the claim of Chap ellier that the p erio d has
b een constant except for sudden jumps in and and again in Chap ellier
and Garrido Pigulski has derived the prop erties of the binary star orbit
including an orbital p erio d of years
In order to distinguish b etween the two prop osed b ehaviors of this star a linear
ephemeris was t to the previously published timings of maximum b etween and
and the residuals computed for all timings since these are shown in Figure
The diamond symbols in the gure represent timings used in the linear t while the
pluses represent eras in which a di erent ephemeris must b e used It can b e seen that the
residuals are t well by three straight lines but the residuals predicted from a quadratic
ephemeris also agree reasonably well esp ecially if a p erio dic variation on either side of
the quadratic is allowed for
Figure gives a metho d of determining which of the two types of ephemeris is the
correct one If the quadratic with variations ephemeris is correct the gure predicts
that there must b e another increase in the p erio d by ab out seconds at HJD ab out
or in the year If the piecewise linear ephemeris is correct there is no way
to predict when the next p erio d change will o ccur or the magnitude or even the sign of
the change Thus the monitoring of this star for the next ten years b ecomes imp ortant
to distinguishing the correct ephemeris form
Andrew P ODELL
Northern Arizona University
Dept of Physics and Astronomy
Flagsta AZ U S A
Internet o dell nauvax ucc nau edu
References
Chap ellier E Astron Astrophys
Chap ellier E and Garrido R Astron Astrophys
Odell A P P A S P
Pigulski A Astron Astrophys
Sterken C Young A Furenlid I Astron Astrophys
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
December
HU ISSN
UBV OBSERVATIONS OF AB Dor
The p eculiar active co ol dwarf AB Dor HD SAO has received con
siderable international attention in recent years cf Vilhu et al b eing the target
of several multi site multi wavelength campaigns most recently in when the HST
EUVE ASCA and other ma jor facilities were brought into concerted action in its direc
tion
A go o d earlier photometric review is that of Innis et al who supplied the
d
ephemeris Min JD E that has b een generally favoured in
subsequent studies AB Dor has b een usually assigned a p eculiar early K sp ectral type
The star was observed using the automated photometer APT of the Kotipu Place
Observatory Hudson et al on six nights b etween Sep and November
using the UBV lters provided with the SSP photometer of Optec Inc The observation
p erio d overlaps with the recently published data set of Anders and Bos
The partial light curves of these authors for the time interval involved are essentially
con rmed by the APT
The main comparison star was HD V B V U B
sp type K I I I cf SIMBAD with o ccasional checks b eing made on HD also a
K I I I star For this star we derive the following V B V U B
The observations have b een reduced on a PC cf Budding and the resulting
V light curve is presented in Figure This light curve results from binning some
individual data into normal p oints and correcting slightly the magnitudes due to
the small redness excess of the comparison star with resp ect to AB Dor B V
The B and U light curves are essentially similar in shap e to the V one The B
magnitude ranges from at brightest V to at the phases and
corresp onding to the lowest on this V data set Individual B observations have a
scatter of ab out mag i e comparable to that of the raw data in V The U data on
the other hand has a noticeably larger disp ersion up to mag around the phase
region where the raw data quality app ears to b e at its p o orest The U light curve
ranges from ab out to mag The conformities in shap e though slightly greater
ranges in the B and U when set against the V light curve supp ort maculation as a likely
explanation for the photometric b ehaviour The slight reddening at the minimum was
also noted by Bos
These light curves are almost complete though there is a small phase interval close
to the b ottom of the minimum not covered by the present dataset Bos private commu
nication observed this region on Nov just b efore the last APT night presented
here and essentially con rmed the phase magnitude range and shap e of this minimum
Figure
There is a slight di erence in phase of Bos minimum and ours however
which from the shap e of the descending sides would b e lo cated somewhat closer to
Anders minimum which derives from observations a few weeks later is still earlier
in phase close to zero in fact Hence there is a suggestion from these three data sets
which range over the later months of of a tendency for the sp ot s asso ciated with
the maculation to have drifted slightly backwards in phase relative to the ephemeris of
Innis et al while preserving the overall shap e of the photometric e ect
E BUDDING
G HUDSON and
R HUDSON
Carter and Kotipu Place
Observatories
Wellington New Zealand
References
Anders G J IBVS No
Bos M IBVS No
Budding E An Introduction to Astronomical Photometry Cambridge Univ Press
Cambridge
Innis J L Thompson K Coates D W and Lloyd Evans T Mon Not Roy
Astron Soc
Hudson G Hudson R and Budding E Proc IAU Col l Posters eds I S
Elliott and C J Butler Dublin Institute for Advanced Studies
Vilhu O Tsuru T Cameron A C Budding E Banks T Slee O B Ehrenfreund
P and Foing B H Astron Astrophys
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
THE ND NAME LIST OF VARIABLE STARS
The present nd Name List of Variable Stars compiled in the manner rst introduced
in the th Name List IBVS No contains all data necessary for identi cation
of new variables nally designated in The total number of designated variable
stars has now reached
The nd Name List consists of two tables Table contains the list of new variables
arranged in the order of their right ascensions It gives the ordinal number and the
designation of each variable its equatorial co ordinates for the equinox the range
of variability sometimes the column Min gives in parentheses the amplitude of light
variation and the system of magnitudes used the symbol Ic means magnitudes in
Cousins I system the symbols y b Str omgren s y b magnitudes the type of
variability according to the classi cation system describ ed in the forewords to the rst
three volumes of the th GCVS edition with the additions introduced in the th Name
List IBVS No and in the th Name List IBVS No and
one addition describ ed b elow two references to the reference list which follows Table
the rst reference is to the investigation of the star the second one indicates the pap er
containing a nding chart or the corresp onding Durchmusterung BD CoD or CPD
containing the variable or the Hubble Space Telescope Guide Star Catalog GSC if
the star can b e found using it
In order not to continue using symbols for comparatively long p erio d pulsating
B stars p erio ds exceeding one day see the st Name List IBVS No we
introduce for such variables a provisional type LBV
In a small number of cases the value of the variability amplitude column Min
in parentheses could not b e expressed in the same system of magnitudes as the star s
brightness in such cases we indicate the photometric band for the amplitude separately
an asterisk in the corresp onding p osition for V Cyg means the amplitude measured
in white light
Table contains the list of variables arranged in the order of their variable star names
within constellations After the designation of a variable its ordinal number from Table
is given as well as identi cations with several ma jor catalogues and identi cations nec
essary to nd this star in the pap ers with the rst or indep endent announcement of the
discovery of its variability References to such pap ers are given in square brackets after the
corresp onding identi cation The name of the discoverer accompanies the reference only
in the case of its b eing di erent from the name of the author s of the pap er referred to
For the stars having NSV catalogue numbers the references to discovery pap ers already
taken into account in the NSV catalogue are not always given After the identi cations some minimal remarks are given if necessary
Several new corrections to earlier Name Lists have b een found In the th Name
List IBVS No Table p there is an obvious misprint in the GCVS
name of the star No instead of V Tau read V Tau In the same Table p
the classi cation given for the star No V Nor actually refers to another star
named only in the present nd Name List as V Nor the most probable variability
type for V Nor is M In Table p for IW Peg add identi cation with NSV
In the th Name List IBVS No Table p add identi cation with
AFGL for V Tau p identi cations with IRC and Gliese should
b e added for UMa Three corrections refer to the st Name List IBVS No
Rather regretfully one of them is connected with a correction to the Name List
No this correction p deals with KR Peg not KP Peg Identi cations of Table
for V Ori p should b e added with TSN and Haro In the same Table
add He to identi cations for LX Vel p
Thanks are due to S V Antipin for his assistance in GSC identi cations and p ositional
determinations to E N Pastukhova for help during the preparation of the computer
version of the present Name List and to members of the GCVS team who prepared
information for the variable star data base
E V KAZAROVETS
N N SAMUS
Institute of Astronomy
of Russian Academy of Sciences
Pyatnitskaya Str
Moscow Russia
Table
No Name R A Decl Max Min Type Ref
h m s o m m
CO Tuc V RRC
BU Cet K RS BD
BV Cet V ZZ
PZ And V ACV BD
V Cas B I
EP Eri V RS BD
XY Ari J NL EA X
V Cas P SR BD
V Per V E
V Per U UV
V Per U UV
epsil Eri V BY BD
V Per P LB BD
V Tau U UV
BU Hyi B RR
BV Hyi B RR
V Tau V RS
BW Hyi B RRAB
BX Hyi B RRC
V Tau U UV
BY Hyi B RRAB
V Tau V INT
V Tau U INT
V Tau V INT
V Tau U INT
V Per V XND ELL
V Tau V INT
V Tau V INT
EQ Eri V DSCT CoD
V Tau V INT
V Tau V INT
V Tau V INT
V Tau V INT
V Tau V INT
V Tau V INT
TV Ret B UG
V Tau V INT
V Tau V INA BD
AK Dor B RR
V Tau V E
V Aur V INT
V Aur V INT
V Aur V I BD
V Ori V EA GS WD BD
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Aur P SR GSC
V Ori U UVN
V Aur P SR GSC
V Aur P SR BD
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori y INA BD
V Ori U UV
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori P UVN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori Ic IN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori U UVN
V Ori P IB GSC
V Ori U UVN
V Ori U UVN
V Ori U UVN
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Ori P UVN
V Ori V INT
V Ori U INT
V Ori U UVN
TZ Col V RS CoD
V Ori V INA
V Mon B BD
UV Lep B V ACVO BD
V Mon B INT
V Ori V INA
V Mon V IA
V Mon V INA
V Mon V INA
PP Gem P SR
HT CMa V IA
HU CMa V IA
HV CMa J M
HW CMa y EA BD
HX CMa J M
BK CMi B SR BD
BL CMi P E
V Pup V INT GSC
V Mon Ic EW
V Mon Ic EW KW
V Mon Ic EW KW
V Mon Ic EW KW
V Mon Ic EW KW
V Mon Ic EW KW
V Mon Ic EW
V Mon Ic E
V Mon Ic EW KW
V Mon Ic EW KW
V Mon Ic EW KW
V Mon Ic EW KW
V Pup J SR CoD
PQ Gem B XPM
CD Cam V EW
FF Cnc V EA
EQ UMa V EW KW
FG Cnc U UV
FH Cnc U UV
BK Lyn V NL
LY Vel V LBV CoD
ER UMa V UG
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
ES UMa V EW
LZ Vel V RS CoD
MM Vel B XND
ET UMa B ACV BD
V Car V BCEP CPD
V Car J SRC
TU Crt B UGSU
V Cen V BE CPD
V Cen V EB CPD
V Cen I CEP
V Cen I CEP
EU UMa B AM
V Cen I CEP
V Cen L M
V Cen I CEP
CI Cru I CEP
CK Cru I CEP
CL Cru K M
CM Cru J M
BP CVn P SR
DK Cha J INA
CN Cru B EB
IP Com V RRAB
V Cen V EB
V Cen V EB
EV UMa V AM
V Cen K M
V Cen I CEP
V Cen I CEP
V Cen I CEP
V Cen b E CPD
HX Lup V ELL CoD
HY Lup V N
sigma Lup V ELL CoD
V Cen H M
ER Dra V DSCTC BD
HZ Lup U V ACV CoD
delta Cir V ELL CPD
II Lup H M
ES Dra P NL
theta CrB V BE BD
IK Lup V INT
V Nor J LB
IL Lup V XNG
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
IM Lup y INT
V Her V BE BD
V Nor B ZAND
UY CrB P RR
V Sco V INT
V Sco V INT
V Sco V INT
V Nor K M
V Her V E
V Sco V ELL CoD
V Ara B ACVO CoD
V Sco K M
V Sco H M
V Sco J SR
V Oph V BY BD
V Sco V EB CoD
V Her U UV
V Ara V E CoD
V Sco L M
V Sco L SR
V Ara V CPD
V Sco H M
V Sco J M
V Sco b EB CoD
V Sco K SR
V Sco J M
V Sco H SR
V Oph B XND
V Oph K M
V Oph V NA
V Oph K M
V Sco K SR
V Sco V RS CoD
V Oph K M
V Sco L SR
V Sco J SR
V Oph B RRC
V Oph V BY
V Sco B UV
V Sco B UV
V Sco B UV
V Sco B UV
V Sgr J SR
V Sco B UV
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
ET Dra U FKCOM BD
V Sco B UV
V Oph V ELL BD
V Oph V E AM
V Sgr V E BD
V Sgr V INA
V Sgr V INA
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B EW
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B EW KW
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B EA
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B EA
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B EA
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Oph K M
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B DSCT
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRC
V Sgr B EA
V Sgr B RRAB
V Sgr B DSCT
V Sgr B RRAB
V Sgr B RRAB
V Sgr B EA
V Sgr B RRAB
V Sgr B RRAB
V Sgr B EA
V Sgr B RRAB
V Sgr B RRAB
V Sgr B RRAB
V Sgr V NA
V Sgr H M
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Sgr J M
NW Ser U BE BD
V Sgr J M
V Sct J SR
V Sgr J M
NX Ser K M
V Oph VB SR
V Lyr B SRB BD
V Aql I M
V Lyr V UG
V Sgr V
V CrA V INT
V Lyr P UG
V Aql J M
V Lyr V M
V Vul V M
V Lyr V SR
V Lyr V IB
V Lyr V IB
V Lyr V SR
V Vul V SR
V Vul V M
V Aql V NA
V Vul V M
V Lyr B SRD
V Lyr V M
V Lyr V M
V Lyr V M
V Aql J M
V Vul V SR
V Vul V M
V Vul V SR
V Vul V M
V Vul V IB
V Lyr V SRB
V Vul V SR
V Lyr V M
V Aql J M
V Cyg V M
V Vul V M
V Vul V M
V Cyg V M
V Vul V M
V Cyg V SR
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Pav B EA NL
V Sgr V DSCT BD
V Cyg V M
QS Tel V AM
V Vul V M
V Vul V IB
V Vul V M
V Cyg V M
V Cyg V M
V Cyg V M
V Cyg V M
V Cyg V SRA
V Cyg V SRA
V Vul V M
V Cyg V M
V Vul V M
V Cyg V M
V Vul V M
V Cyg V M
V Vul V SR
V Cyg V SR
V Vul V SR
V Cyg V M
V Vul V M
V Vul V M
V Vul V SRB
V Cyg V SR
V Vul V IB
V Cyg V SRA
V Cyg V M
V Cyg V M
V Cyg V M
V Vul P NL
V Cyg V I
V Cyg V SR
V Vul V M
V Cyg V M
V Cyg V RS BD
V Cyg V M
V Aql V BY BD
V Aql V RS BD
V Vul V IB
V Cyg V M
V Vul V M
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
V Aql V EA BD
V Vul V M
V Cyg B BD
V Vul V M
V Vul V M
V Cyg P LB BD
V Vul V M
V Vul V SRA
V Vul K M
V Cyg V SR
V Vul V SR
V Vul V SRD
V Vul V SR
V Vul V M
V Cyg b B BCEP BD
V Cyg b B ACV BD
LV Del V RV
V Cep b B EA BD
V Cyg V INA
V Cyg V INA
V Cyg V INA
V Cyg V INA
V Cyg V INA
V Cyg V EA BD
V Cyg V INA
V Cyg V INA
V Cyg V INA
V Cyg V INA
V Cyg V INA
V Cep U INA
HU Aqr V XRM E
V Cyg V ZZO
V Cep V LC BD
V Cep V BE BD
HV Aqr V EW KW RS BD
KY Peg P SR BD
V Cep V EB
V Cep I M
V Lac B SRB
V Cep V INA
V Lac b B LBV BD
V Cep V SR
KZ Peg J M
V Cep b B LBV BD
Table continued
No Name R A Decl Max Min Type Ref
h m s o m m
CG Gru V EW KW
V Cep V DSCT BD
QQ And P SR BD
LL Peg K M
LM Peg P SR BD
V Cas V NA
HW Aqr B ZZA
Table
PZ And And Winzer HR HD A p SAO NSV
QQ And BD ADS
HU Aqr RX RXJ RE GSC
HV Aqr BD Hutton GSC
HW Aqr EC
V Aql IRC AFGL IRAS CCS NSV
V Aql IRC AFGL IRAS CCS NSV
V Aql Nova Aql Yamamoto
V Aql IRC AFGL IRAS NSV
V Aql AFGL IRAS
V Aql HD K BD SAO IRAS
V Aql HD G BD SAO
V Aql HD A BD SAO
V Ara HD A CoD CPD SAO
V Ara HD B CoD CPD SAO
LSS NSV
V Ara CPD IRAS He PNN RCB like
minima
XY Ari H H
V Aur LkCa HBC NTTS TAP
V Aur HBC NTTS TAP NW
V Aur Aur HR HD F BD SAO
ADS A Gliese IRAS
V Aur DHK IRAS GSC
V Aur DHK IRAS GSC
V Aur DHK HD Mb BD SAO
IRC IRAS
CD Cam Comparison star c for UY Cam
FF Cnc GSC
FG Cnc Ton Prf
FH Cnc Ton Prf
BP CVn DHK Wr GSC CSV NSV
HT CMa LkH HBC IRAS
HU CMa LkH HBC IRAS
HV CMa AFGL IRAS
HW CMa HD A BD CoD CPD
SAO
Table continued
HX CMa AFGL IRAS
BK CMi DHK BD SAO IRC IRAS
BL CMi P CSV NSV
V Car HD B Lampens CoD CPD
SAO
V Car OH IR IRAS OH
V Cas M
V Cas DHK BD IRC AFGL S IRAS
Zi CSV NSV
V Cas Nova Cas Kanatsu
V Cen CPD
V Cen HD B CoD CPD SAO
IDS S LSS CSV NSV Erro
neously named HD in
V Cen
V Cen
V Cen
V Cen IRAS
V Cen
V Cen LSS
V Cen LSS
V Cen OH IR IRAS OH
V Cen
V Cen
V Cen
V Cen HR HD B CoD CPD
SAO
V Cen OH IR IRAS OH
V Cep HR HD B BD SAO
IRAS
V Cep HD B BD SAO MWC HBC
Zi CSV NSV In ref neb NGC
V Cep HR HD K BD SAO
ADS IRC AFGL IRAS
V Cep Cep Szabados Kun HR HD B p BD
SAO MWC IRAS According to
vis during JD
V Cep HD B BD SAO NSV
V Cep AFGL IRAS
V Cep LkH HRC NSV
V Cep TAV Col lins IRC AFGL IRAS
V Cep HR HD B BD SAO
ADS
V Cep HR HD A BD SAO
IRAS
BU Cet Cet HR HD G BD SAO ADS
A Gliese A IRAS RE P CSV
NSV
BV Cet Feige G Gr WD BPM
PHL L LP
DK Cha IRAS
Cir Cir Cousins HR HD Oe CoD
CPD SAO IDS S LSS CSV
NSV
TZ Col HD G CoD CPD SAO
H
IP Com Case SVS CSV NSV
Table continued
V CrA CoD CPD HBC Wa CrA
UY CrB Wr CSV NSV
CrB CrB CrB HR HD B BD SAO
MWC IRAS NSV
TU Crt J
CI Cru
CK Cru
CL Cru IRSV IRAS
CM Cru OH IR IRAS OH
CN Cru CPD I I I NGC
V Cyg LD GSC
V Cyg LD IRAS
V Cyg LD
V Cyg LD
V Cyg LD
V Cyg TAV Col lins LD IRAS AFGL
CCS IRC GSC Q
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg LD
V Cyg LD
V Cyg LD IRAS GSC
V Cyg LD IRAS GSC
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg LD GSC
V Cyg LD IRAS
V Cyg LD GSC
V Cyg LD IRAS GSC
V Cyg LD IRAS
V Cyg Cyg HR HD K BD
SAO IRAS
V Cyg LD IRAS
V Cyg LD IRAS
V Cyg HD B BD SAO LS I I
d d
NSV Periodic P variability of an O Vnfp SB P
or b
star
V Cyg DHK HD K BD SAO
IRAS
V Cyg LD IRAS
V Cyg Cyg Cyg HR HD B BD
SAO ADS IRAS Similar to Eri
V Cyg HR HD B BD SAO
V Cyg LkH UH NSV
V Cyg LkH CSV NSV
V Cyg AS MH NSV
V Cyg LkH AS NSV
V Cyg LkH AS MH UH NSV
V Cyg DHK BD SAO
V Cyg LkH NSV
V Cyg LkH NSV
V Cyg LkH
V Cyg LkH NSV
V Cyg LkH NSV
Table continued
V Cyg RXJ Watson white light amplitude
LV Del New var near HR Del
AK Dor R
ER Dra HR HD F BD SAO
IRAS
ES Dra PG
ET Dra BD E E MS
GSC
EP Eri HR HD G BD SAO IRAS
Gliese LTT NSV
EQ Eri HD F CoD CPD SAO
Eri Eri Eri HR HD K BD
SAO IRC AFGL IRAS Gliese
LFT
h m s 0
PP Gem DHK Gem Wr IRAS
CSV NSV
PQ Gem RE REJ
CG Gru V
V Her Her HR HD B BD
SAO MWC
V Her Zi CSV NSV
V Her BD SAO IRAS
BU Hyi No
BV Hyi No
BW Hyi No
BX Hyi No
BY Hyi No
V Lac P IRAS CSV NSV
V Lac HR HD B BD SAO
CSV NSV
UV Lep HD A BD SAO
HX Lup HR HD B CoD CPD
SAO LSS
HY Lup Possible Nova in Lupus Lil ler Nova Lup
HZ Lup HR HD A p CoD CPD
SAO
II Lup IRAS
IK Lup Sz HBC IRAS
IL Lup Optical counterpart of the transient X ray source U
IM Lup HBC Sz The IRAS
Lup Lup HR HD B CoD CPD
SAO IRAS
BK Lyn PG CBS Ton
V Lyr DHK HD Mb BD SAO
IRC AFGL IRAS
V Lyr LP LHS
V Lyr UG type var S
V Lyr LD IRAS
V Lyr LD IRAS GSC
V Lyr LD
V Lyr LD GSC
V Lyr LD IRAS GSC
V Lyr Var
V Lyr LD IRAS
V Lyr LD IRAS
V Lyr LD
V Lyr LD IRAS
V Lyr LD IRAS
Table continued
V Mon HR HD B p BD SAO
MWC IRAS CSV NSV Be star mass
transfer binary with recurrent shell events
V Mon Bretz in GGD HRC GSC NSV
V Mon LkH HRC NSV
V Mon LkH HBC AFGL IRAS
V Mon HD B BD SAO HBC
MWC LS VI RAFGL S IRAS
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Mon V op en cluster Be
V Nor IRAS IRSV
V Nor Possible Nova in Norma Lil ler Nova Nor Liller s variable
in the vicinity of NSV IRAS
V Nor IRAS
V Oph HD G BD SAO Gliese
G LFT
V Oph X ray Nova in Ophiuchus Del la Valle Mirabel Cordier Optical
counterpart of X ray transient GRS GRO J X ray Nova
Oph
V Oph IRAS P IRAS
V Oph Nova Oph Camil leri
V Oph IRC IRAS
V Oph IRAS P IRAS
V Oph HV CSV NSV
V Oph P IC V
V Oph HD A BD SAO
V Oph H Remillard
V Oph IRAS P IRAS
V Oph TAV IRAS
V Ori HD K p Wing BD SAO
IRC CSS AFGL IRAS
V Ori Ton Tof GSC
V Ori Ton Tof GSC
V Ori Ton Tof
V Ori Ton Tof
V Ori Ton Tof
V Ori Ton Tof
V Ori Ton Tof GSC
V Ori Ton Tof
V Ori Ton Tof
V Ori HD A BD HBC IRAS
V Ori Ton Tof GSC
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
Table continued
V Ori JW
V Ori JW
V Ori Ton Tof
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori JW
V Ori Ton Tof GSC
V Ori TSN Haro H IRAS CSV NSV
Kiso Area A No
V Ori Ton Tof
V Ori Ton Tof
V Ori DHK GSC
V Ori Ton Tof GSC NSV
V Ori Ton Tof TSN Haro H Kiso Area A
No
V Ori Ton Tof GSC
V Ori Ton Tof
V Ori HRC TSN Haro H Haro IRAS
NSV
V Ori HRC TSN Haro IRAS GSC
NSV
V Ori Ton Tof GSC
V Ori HD A BD HRC MWC
IRAS NSV
V Ori MWC HRC LSS Central star of PN Sh
IRAS NSV
V Pav EC
KY Peg DHK BD BV CSV NSV
KZ Peg IRC AFGL IRAS NSV
LL Peg CRL AFGL IRAS
LM Peg DHK BD SAO IRAS
V Per Comparison star A for AP Per cluster
V Per FS in the Per cluster region
V Per FS in the Per cluster region
V Per DHK HD G BD SAO
IRC IRAS
V Per GRO J X ray Nova Per
V Pup PDS Wray IRAS GSC
V Pup CoD CPD SAO IRC
AFGL S IRAS A GSC NSV Sp
A SAO is doubtful
TV Ret R
V Sgr OH IR OH CRL IRAS
V Sgr HD B BD CoD CPD
SAO LSS IRAS BV
NSV
V Sgr CoD CPD LkH K W NGC V J NGC
Table continued
V Sgr LkH HRC LSS NSV
V Sgr F NGC Field star
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr F NGC Field star
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var P HV CSV NSV
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var
Table continued
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
Table continued
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var E
V Sgr Var
V Sgr Var
V Sgr Var
V Sgr Nova Sgr Sugano Lil ler
V Sgr IRAS
V Sgr IRAS To E from V Sgr close to it
V Sgr IRAS Not identical with V Sgr
V Sgr IRAS Not identical with V Sgr
V Sgr Nova Sgr Yamamoto Luminous red variable in Sgr A red star
with a nova like outburst
V Sgr HR HD A BD CPD
SAO
V Sco HBC Wa Oph GSC
V Sco HBC Wa Oph GSC
V Sco HBC Wa Oph GSC
V Sco HR HD B CoD CPD
SAO
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco HD B CoD CPD SAO
IDS S Seggewiss NGC Braes NGC
CSV NSV
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco HD B CoD CPD SAO
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS
V Sco OH IR OH IRAS Not
identical with V Sco
V Sco HD F A CoD CPD
SAO EXOSAT
V Sco OH IR OH IRAS
AFGL
V Sco OH IR OH AFGL
IRAS
V Sco No M
V Sco No M
V Sco No M
V Sco No M
V Sco No M
V Sco No M
V Sct OH IR H AFGL IRAS
Table continued
NW Ser HR HD B BD SAO
MWC NSV
NX Ser AFGL IRAS
V Tau Nos
V Tau HI I
V Tau No Co ordinates in are wrong
V Tau WTT NTTS N S TAP
HBC
V Tau LkCa HBC
V Tau TAP HBC NTTS
V Tau LkCa HBC TAP NTTS
V Tau LkCa HBC
V Tau TAP HBC NTTS
V Tau TAP
V Tau TAP HBC NTTS
V Tau TAP HBC NTTS L
V Tau TAP HBC NTTS L
V Tau TAP HBC NTTS
V Tau TAP S NTTS
V Tau LkCa HBC IRAS
V Tau BD
V Tau HD B BD SAO NSV
QS Tel RE
CO Tuc HV NGC V Globular cluster NGC Tuc
Not cluster member not SMC member
EQ UMa New variable in the SW UMa eld
ER UMa PG Iida GSC
ES UMa GSC
ET UMa H UMa HR HD A BD SAO
IRAS Zi CSV NSV
EU UMa RE
EV UMa RE
LY Vel HD B CoD CPD SAO
LZ Vel HD K CoD CPD
SAO IRAS
MM Vel X ray Nova in Vela Del la Valle Benetti Optical counterpart of
GRC
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD IRAS
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD
V Vul LD IRAS
V Vul LD IRAS
V Vul LD
V Vul LD
V Vul LD IRAS IRC GSC
V Vul LD IRAS
Table continued
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD IRAS
V Vul LD
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD AFGL IRAS
V Vul LD IRAS
V Vul LD IRAS
V Vul E Not identical with QQ Vul
V Vul LD
V Vul LD IRAS
V Vul LD IRAS
V Vul LD IRAS GSC
V Vul LD IRAS
V Vul LD IRAS
V Vul LD IRAS
V Vul LD
V Vul IRAS
V Vul LD IRAS
V Vul LD
V Vul LD IRAS
V Vul LD IRAS
References
S J Adelman R J Dukes D M Pyper AJ No
D B Wil liams B A Ski IBVS No
A D Schwope H C Thomas K Beuermann AsAp No L
R M Robb IBVS No
R S Stobie A Chen D O Donoghue D Kilkenny MN No L
A Alksnis D Zaime Issledovanie Solntsa i Krasnych Zvezd No
T Le Bertre AsAp Suppl No
Hideo Maehara Takao Soyano NAO Japan Publ No
IAU Circ No
The Astronomer No
M Cohen L V Kuhi PASP No
D S Hal l G W Henry AJ No
E W Burke Jr B Etter R Fried T J Kreidl IBVS No
P Martinez D W Kurtz IBVS No
J W Menzies F Marang J E Westerhuys SAAO Circ No
D L Pol lacco D Kilkenny F Marang F van Wyk G Roberts MN No
B Zuckerman E E Becklin I S McLean J Patterson ApJ No
D P Clemens R W Leach ApJ No
J Bouvier S Cabrit M Fernandes E L Martin J M Matthews AsAp No
E D Feigelson J M Jackson R D Mathieu P C Myers F M Walter AJ No
K Krisciunas C Aspin T R Geballe H Akazawa C F Claver E F Guinan H J Landis K D Luedeke
N Ohkura O Ohshima D R Skil lman MN No
D H Kaiser IBVS No
P Broglia P Conconi IBVS No
E A Baker MN No
P Pravec IBVS No
G Gonz ales C Escamilla E Parsamian IBVS No
R Weber IBVS No
V S Shevchenko Herbig Ae Be Stars Tashkent Fan
G H Herbig ApJ Suppl No
Liu Qingyao J Andersen J V Clausen B Nordstr om R P Stefanik IBVS No
M J Lebofsky S G Kleinmann AJ No
D H Kaiser IBVS No
A Paschke BBSAG Bull No
C Ho meister Sonn Mitt No
D Heynderickx AsAp Suppl No
T Le Bertre AsAp Suppl No
V Gasperoni P Ma ei G Tosti IBVS No
IAU Circ No
G M Hurst The Astronomer No
L A Balona MN No
P Mayer R Lorenz H Drechsel IBVS No
P L Schechter I M Avruch J A R Caldwel l M J Keane AJ No
D Kilkenny F van Wyk F Marang G Roberts K Sekiguchi IBVS No
C B Stephenson N Sanduleak Warner and Swasey Publ No
M Jerzykiewicz AsAp Suppl No
V S Shevchenko M A Ibragimov S D Yakubov Soviet Astronomy No
E M Halbedel PASP No
IAU Circ No
V A Bartalog MS
R Gr obel IBVS No BAV Mitt No
G H Herbig N K Rao Lick Contr No
D B ohme MVS H
Hao Jinxin Huang Lin IBVS No
Wang Gang Hu Jingyao Qian Zhongyu Zhou Xu AAp Sinica No
N Achilleos D T Wickramasinghe J Liebert R A Sa er A D Grauer ApJ No
H L Giclas R Burnham Jr N G Thomas Lowell Bull No
J D Hughes P Hartigan J A Graham J P Emerson F Marang AJ No
J D Hughes J P Emerson H Zinnecker P A Whitelock MN No
D J Stickland R H Koch I Pachoulakis R J Pfei er Obs No
K G Strassmeier H M Maitzen M Pranka IBVS No
T D Kinman Invited pap er IAU Coll No July Victoria B C
N E Kurochkin Perem Zvezdy No
E Covino L Terranegra M Franchini C Chavarria K R Stalio AsAp Suppl No
I S Glass M V Penston MN No
S Yu Shugarov IBVS No
G Guerrero M Bossi M Scardia AsAp No
M L Hazen IBVS No
J Maza L E Gonzalez M Wischnjewsky F Barrientos PASP No
Ch Koen MN No
H C Arp C T van Sant AJ No
L Dahlmark IBVS No
The Astronomer No
J T Hooten D S Hal l ApJ Suppl No
A A Barannikov Astronomy Letters No
D B Wil liams IBVS No
G H Herbig ApJ No
Ch L Perry A U Landolt AJ No
D H Kaiser M E Baldwin IBVS No
G Vauclair J A Belmonte B Pfei er M Chevreton N Dolez C Motch K Werner M W Pakul l AsAp
No L
C Motch K Werner M W Pakul l AsAp No
R K Honeycutt J W Robertson D N Vesper B D Kern G W Turner J R Pier IBVS No
T D Kinman L L Stryker J E Hesser J A Graham A R Walker M L Hazen J M Nemec PASP
No
Li Zhiping Jiang Shiyiang AsAp Suppl No
I L Andronov IBVS No
R A Downes M M Shara PASP No
L Jetsu R Anttila E Dmitrienko K N Grankin J Huovelin S Yu Melnikov V S Shevchenko I Tuominen
AsAp No
G Cutispoto AsAp Suppl No
C Koen G Roberts IBVS No
G J Frey B Grim D S Hal l P Mattingly S Robb J Wood K Zeigler AJ No
R Weber DOC No
K O Mason M G Watson T J Ponman P A Charles S R Duck B J M Hassal l S B Howel l M Ishida
D H P Jones J P D Mittaz MN No
D Cieslinski F J Jablonski IBVS No
J R Percy A Attard PASP No
R de Martino Ch J Predom JAAVSO No
AAVSO Variable Star Atlas
R K Konstantinova Antova A P Antov M M Ivanov IBVS No
S Yu Shugarov A V Savenkov IBVS No
P Martinez D W Kurtz R Ashley IBVS No
M Jerzykiewicz C Sterken AsAp No
IAU Circ No
T Lanz D A Bohlender J D Landstreet IBVS No
P J Meadows A R Good R D Wolstencroft MN No p
R D Schwartz P Noah AJ No
R D Schwartz ApJ Suppl No
M Del la Valle L Pasquin IAU Circ No
H Pedersen The Messenger No
G F Gahm E Gul lbring C Fischerstr om K P Lindroos K Lod en AsAp Suppl No
Pik Sin The Bosscha Contr No
D R Skil lman J Patterson ApJ No
D G Monet C C Dahn F J Vrba H C Harris J R Pier C B Luginbuhl H D Ables AJ No
W Wenzel IBVS No
A P Katsyka N N Samus IBVS No
S J Adelman PASP No
R Carballo C Eiroa AsAp No
K G Dzhakusheva K S Kuratov D B Mukanov Yu K Bergner A S Miroshnichenko R V Yudin N Yu
Yutanov Soviet Astronomy Letters No
J Kaluzny B Mazur W Krzeminski MN No
IAU Circ No
H W Duerbeck Space Sci Rev Nos
V Reglero J Fabregat A de Castro IBVS No
IAU Circ No
B Carter F Marang P A Whitelock R M Catchpole M W Feast SAAO Ann Rep p
IAU Circ No
A Paschke BBSAG Bull No
D A Mitrofanov Perem Zvezdy No
C F Prosser AJ No
M F McCarthy S J S O Sul livan S J Ric Astr No
A D Silber R A Remillard K Horne H V Bradt ApJ No
M Col lins The Astronomer No
A Jorissen M Mayor J Manfroid C Sterken IBVS No
E S Parsamian E Chavira G Gonz alez Rev Mex No
E A Bibo P S The AsAp Suppl No
J M Attridge W Herbst ApJ No L
B F Jones M F Walker AJ No
V S Shevchenko S D Yakubov Soviet Astronomy No
E S Parsamian E Chavira Ton Bol No
V S Shevchenko S D Yakubov Soviet Astronomy No
D A H Buckley D O Donoghue R S Stobie R A Remillard MN No
C F Prosser IBVS No
E H Semkov K P Tsvetkova M K Tsvetkov C F Prosser IBVS No
A J Castro Tirado E P Pavlenko A A Shlyapnikov S Brandt N Lund J L Ortiz AsAp No L
J Grigorio Hetem J R D L epine G R Quast C A O Torres R de la Reza AJ No
D A Al len A R Hyland A J Longmore J L Caswel l W M Goss R F Haynes ApJ No
G H Herbig ApJ No
M L Hazen AJ No
B M Blanco AJ No
IAU Circ No
P Whitelock M Feast R Catchpole MN No
IAU Circ No
IAU Circ No
D W Kurtz J Egan ApSS No
F M Walter ApJ No
G Cutispoto G Tagliaferri P Giommi C Goui es R Pal lavicini L Pasquini M Rodon o AsAp Suppl
No
K L Jones A A Page Pro c ASA No
T Le Bertre AsAp No
T Le Bertre N Epchtein C Goui es M Heydari Malayeri C Perrier AsAp No
J Kelemen IBVS No
C F Prosser R E Schild J R Stau er B F Jones PASP No
E Hertzsprung Leiden Ann part A
F J Vrba P F Chugainov W B Weaver J S Stau er AJ No
G H Herbig F J Vrba A E Rydgren AJ No
K N Grankin IBVS No
L L Chinarova I L Andronov Astron Tsirk No
D A N Buckley D O Donoghue B J M Hassal l B J Kel lett K O Mason K Sekiguchi M G Watson P J
Wheatley A Chen MN No
M W Feast A D Thackeray A J Wesselink MN No
S W Lee AsAp Suppl No
J A De Young R E Schmidt IBVS No
G M Hurst The Astronomer No
Z Mikul a sek D Han zl IBVS No
F A Catalano F Leone AsAp No
J P D Mittaz S R Rosen K O Mason S B Howel l MN No
J P Osborne A P Beardmore P J Wheatley P Hakala K O Mason B J M Hassal l A R King Cataclysmic
Vars and Rel Physics Annals of the Israel Physical So ciety No
A M van Genderen F C van den Bosch F Dessing R van der Heiden J P de Jong R L J van der Meer
R van Ojik J M Smit M J Zijderveld AsAp No
T R Scott J B Hearnshaw R D Watson P M Kilmartin A C Gilmore JApAs No
IAU Circ No
I L Andronov MVS H
L O Takalo J A Nousek PASP No
P J Hakala M G Watson O Vilhu B J M Hassal l B J Kel lett K O Mason V Piirola MN No
B Vet o W Sch oneich Yu S Rustamov AN No
W A Lawson A F Jones Obs No
M M Zakirov A A Azimov K N Grankin IBVS No
K Krisciunas E Guinan IBVS No
P Frank IBVS No
A Ardeberg E Maurice AsAp Suppl No
B E Westerlund R Garnier AsAp Suppl No
J S Dril ling ApJ Suppl No
D Engels IBVS No
Yu K Bergner A S Miroshnichenko R V Yudin N Yu Yutanov K S Kuratov D B Mukanov Astron Tsirk
No
Yu S E mov Izv Krym Astr Obs
W Wenzel IBVS No
S M Jakate AJ No
F C Fekel D S Hal l IAPPP Comm No
J R Percy M G Richer H Bo zi c P Harmanec J Horn P Koubsk y S K r z L A Kelsey D B Ho H J
Landis R C Reisenweber R Wasson IBVS No
J E Winzer Ph D Thesis Univ Toronto
IAU Circ No
E A Bergin M L Fritz E F Guinan G Innel la H Leckenby G P McCook B J Hrivnak BAAS No
H J Landis H P Lovell D S Hal l D G Uckotter AA No
IAU Circ No
H Pedersen M V eron P V eron H E Schuster IAU Circ No
D vander Linden C Sterken AsAp Suppl No
S B Howel l P Szkody T J Kreidl D Dobrzycka PASP No
D C Whittet J K Davies A Evans M F Bode E I Robson R M Ban eld SAAO Circ No
M A Pogodin Soviet Astronomy No
T Le Bertre N Epchtein M Heydari Malayeri AsAp No
J D Dorren E F Guinan AJ No
R R Radick M S Wilkerson S P Worden J L Africano A Klimke S Ruden W Rogers T E Armandro
M S Giampapa PASP No
P Whitelock M Feast MN No p
P Whitelock MN No p
R F Wing S B Yorka MN No
Th B Ake III H R Johnson M M Ameen ApJ No
M J Lebofsky G H Rieke AJ No
M V Penston D A Al len C Lloyd Obs No
G N Mandel W Herbst ApJ No L
G C Kilambi AA No
J Herman R Isaacman A Sargent H J Habing AsAp No
D Han zl J Kysel y K Hornoch IBVS No
B W Bopp J Africano R Quigley AJ No
G de Vaucouleurs H G Corwin Jr B A Ski PASP No
J P Osborne A P Beardmore P J Wheatley P Hakala M G Watson K O Mason B J M Hassal l A R
King MN No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
BVR OBSERVATIONS OF THE DOUBLE MODE CEPHEIDS
AS Cas V Sct and BQ Ser
Recently one of us Berdnikov has decomp osed the available photo electric obser
vations of all double mo de Cepheids into two oscillations It was p ointed out as well that
the number of existing observations is not su cient for reliable investigation of light curve
variations for the ma jority of these stars Therefore we continue to carry out observations
of all accessible double mo de Cepheids
Photo electric observations of double mo de Cepheids were carried out in summer
autumn The cm re ector of the Mt Maidanak observatory was used and
BVR measurements of AS Cas Table BVR measurements of V Sct Table
c c
and BVR measurements of BQ Ser Table were obtained
c
This study was partially supp orted by the Russian Foundation for Fundamental Re
search through grants No and No
Table BVR observations of AS Cas
c
JD hel V B V V R JD hel V B V V R
c c
Table cont
JD hel V B V V R JD hel V B V V R
c c
Table BVR observations of V Sct
c
JD hel V B V V R JD hel V B V V R
c c
Table cont
JD hel V B V V R JD hel V B V V R
c c
Table BVR observations of BQ Ser
JD hel V B V V R JD hel V B V V R
c c
Table cont
JD hel V B V V R JD hel V B V V R
c c
M A IBRAGIMOV
L N BERDNIKOV
Astronomical Institute
O V VOZIAKOVA
Astronomicheskaya str
Sternberg Astronomical Institute
Tashkent
Universitetskij prosp
Republic of Uzb ekistan
Moscow Russia
Reference
Berdnikov L N Pis ma Astron Zh
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
UBVR PHOTOELECTRIC OBSERVATIONS OF THE DOUBLE MODE
CEPHEIDS CO Aur TU Cas AND EW Sct
Recently one of us Berdnikov has decomp osed the available photo electric obser
vations of all double mo de Cepheids into two oscillations It was p ointed out as well that
the number of existing observations is not su cient for reliable investigation of light curve
variations for the ma jority of these stars Therefore we continue to carry out observations
of all accessible double mo de Cepheids
Photo electric observations of double mo de Cepheids were carried out in summer
autumn The cm re ector of the Mt Maidanak observatory was used and
UBVR measurements of CO Aur Table UBVR measurements of TU Cas Table
c c
and UBVR measurements of EW Sct Table were obtained
c
This study was partially supp orted by the Russian Foundation for Fundamental Re
search through grants No and No
Table UBVR observations of CO Aur
JD hel V U B B V V R JD hel V U B B V V R
c c
Table cont
JD hel V U B B V V R JD hel V U B B V V R
c c
Table UBVR observations of TU Cas
JD hel V U B B V V R JD hel V U B B V V R
c c
Table cont
JD hel V U B B V V R JD hel V U B B V V R
c c
Table UBVR observations of EW Sct
c
JD hel V U B B V V R JD hel V U B B V V R
c c
M A IBRAGIMOV
L N BERDNIKOV
Astronomical Institute
O V VOZIAKOVA
Astronomicheskaya str
Sternberg Astronomical Institute
Tashkent
Universitetskij prosp
Republic of Uzb ekistan
Moscow Russia
Reference
Berdnikov L N Pis ma Astron Zh
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
PHOTOMETRIC OBSERVATION OF NS MONOCEROTIS
BAV Mitteilungen Nr
NS Mon CSV BD was discovered by Ho meister He
m m
classi ed the variable as p ossibly Algol type in the range b etween : and pg
First investigation of this variable was p erformed by Kipp enhahn based on
plates He found the maximum brightness not to b e constant susp ected Lyr type and
gave three times of minimum light Three additional minima timings were submitted by
Wasiljanowskaja She supp osed the variable to b e of Algol type Variability of the
m m
star b etween : and : pg was con rmed by Weber An investigation on
photographic plates by Olijnyk resulted in times of minimum light of NS
Mon but the elements could not b e found An even larger set of photographic plates was
used by H aussler He investigated this star on plates of the Sonneb erg and
Hartha Sky Patrols and derived rst elements
d
Min I HJD : : E:
Using the estimates on the Sonneb erg plates together with the ab ove elements a rst
photographic lightcurve and an O C diagram were given Unfortunately two weak stars
north and south of NS Mon led to a rather large scatter in the lightcurve NS Mon was
m m
classi ed as W UMa type in the range b etween : and : ph With these ab ove
data NS Mon is listed in the fourth edition of the GCVS Kholop ov et al
For seventeen years the variable had remained obviously unobserved when we put NS
Mon on our program scheduled to lo ok after seldom observed or in some other way
problematic eclipsing binaries
The photo electric observations were made at the private observatory of one of us F A
with a m automatic photo electric telescop e Agerer The photometer was
equipp ed with an unco oled EMI A tub e and Schott lters for B and V SAO
G was used as comparison star and SAO G to check its constancy
One minimum was observed photographically P F with a Lichtenknecker Flat eld
Camera f mm f D on hypered KODAK Technical Pan The exp osures
were evaluated with a xed diaphragm photometer Altogether one new photographic
and photo electric minima in two colours could b e collected All minima times were
calculated with the Kwee van Woerden metho d
In compiling the lightcurve Figure from our data it b ecame evident that the p erio d
published in the GCVS was a spurious one with the relation
:
P P GCVS
Figure Di erential light curves in B and V of NS Mon
computed with resp ect to the new ephemeris
Figure O C diagram for NS Mon computed with resp ect to the new ephemeris
using all available minimum timings represents photo electric
photographic series and photographic plate minima
2
Using all published minima found in the BAV Database of Minima of Eclipsing Bina
ries together with our new observations a weighted least squares t yields the following
linear ephemeris
d
Min I HJD : E
:
Our observations show the primary and secondary minima to b e almost equally deep
m
with an amplitude of : A distinction b etween them was not p ossible If b oth minima
are primary ones the p erio d has to b e halved As can b e seen from the lightcurve NS
Mon is in any case of the type EA
Table
Observed times of minima for NS Mon ep o chs and residuals computed with resp ect to
the ephemeris derived in this pap er
N JD hel W T Ep o ch O C Lit N JD hel W T Ep o ch O C Lit
P F
P P
P P
P P
P P
P P
P V
B P
V P
P B
P B
P V
B P
P V
P B
V P
P B
V P
P F
P V
P B
V P
B P
P V
B P
P V
B P
F
Kipp enhahn Wasiljanowskaja Olijnyk H aussler
Agerer this pap er Frank this pap er
P denotes pg plate min V photo electric min in visual and B in B Filter and F
photographic series Those marked with got reduced weight while those marked with
were discarded
F AGERER
P FRANK
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm
D Berlin Germany
References
Agerer F BAV Rundbrief
H aussler K Mitt B H B urgel Sternw Hartha
Ho meister C Astr Nachr
th
Kholop ov P N et al Gen Cat of Var Stars Ed Nauka Moscow
Kipp enhahn R Astr Nachr
Kwee K K van Woerden H Bul l Astr Inst Netherlands
Olijnyk G T Lvov Circ
Wasiljanowskaja O P Astr Circ
Weber R J des Observateurs
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
AW VIRGINIS PHOTOELECTRIC TIMES
OF MINIMUM AND IMPROVED PERIOD
h m 0
The variable star AW Virginis : : was discovered by
Ho meister Jensch classi ed this star as a W UMa type system based on
the rst photographic light curve He also obtained fourteen times of minimum light and
derived the following ephemeris
d
Min I J D hel : E
Whitney and Ko ch published photographic times of minimum light and
the rst author calculated an orbital p erio d of P days More recently Ho
mann determined two additional photo electric times of minimum
Figure shows the BV light curves obtained in April at Las Campanas Chile
with the cm telescop e of the David Dunlap Observatory and in March at the
Complejo Astronomico El Leoncito CASLEO San Juan Argentina An RCA P
photomultiplier refrigerated by dry ice and a photon counting system were used in the
rst case and the Vatican Observatory photo p olarimeter VATPOL Magalh aes et al
with two dry ice co oled RCA Ga As photomultipliers were employed in the
second
The measurements were made di erentially with resp ect to a comparison star No
variation in the light of this star was detected All the observations were corrected for
rst and second order di erential extinction As the comparison is lo cated very near
to the variable the corrections were small Absolute photometry of the comparison star
allowed to determine a V for the variable star
max
A total of observations in each BV passband were obtained These observations
well cover the orbital p erio d and show minima of approximately the same depth of
mag see Figure From these measurements we determined times of minimum light
times of primary minimum and times of secondary minimum using the bisection
of chords metho d A linear least squares t to our photometric data yields an up dated
ephemeris
d
Min I J D hel : E
We compiled all the previously determined times of minimum as well as those rep orted
is this note Using a linear least squares solution we derived an improved ephemeris
d
Min I J D hel : E
Figure Figure
Table Photo electric times of minimum light of AW Virginis
Min JDhel E O C O C reference
II
I
II
II
II
I
I
I
II
I
I
I
I
I
I
I
I
II
I
I
I
II
II
II
I
I
II
II
I
I
II
II
II
I
I
I
Note Jensch Whitney Ko ch Ho mann this note
Table lists all the times of minimum light used to derive equation The columns
give the Julian date corresp onding to each minimum the ep o ch number and the O C
residuals calculated from equation For the new times of minimum light we included
the residuals derived from equation Figure shows the O C vs E diagram corre
sp onding to equation The residuals are in general randomly distributed and except
for one minimum Ko ch the amplitude of the disp ersion is of days Ac
cording to the precision of the ephemerides the orbital p erio d of the system seems to
have remained practically constant over the last years However additional times of
minimum distributed on a longer time base are needed to con rm this preliminary result
E LAPASSET and
M GOMEZ
Observatorio Astron omico
Universidad Nacional de C ordoba
Laprida C ordoba
Argentina
References
Ho mann M Inf Bul l Var Stars No
Ho meister C Astronomische Nachrichten
Jensch A Astronomische Nachrichten
Ko ch R H AJ
Magalh aes A M Benedetti E and Roland E H PASP
Whitney B S AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
PHOTOELECTRIC UBVR OBSERVATIONS
OF THE PECULIAR CEPHEID V Lyr
We have observed V Lyr at the Mt Maidanak observatory in September Octo
b er The cm re ector was used and UBVR di erential measurements were
c
obtained Table the accuracy of the individual data is near mag in all lters The
magnitude of the comparison star HD in UBVR determined by us is V
c
U B B V V R This star is classi ed as Cepheid with
c
irregularly variable amplitude in the GCVS According to our data the amplitude of light
curve Fig is near mag in V
The phases are calculated with the elements
M axJ D hel E
This study was partially supp orted by the Russian Foundation for Fundamental Re
search through grants No and No
Table
JD hel Phase V U B B V V R
c
Table cont
JD hel Phase V U B B V V R
c
Figure
L N BERDNIKOV
O V VOZIAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
Reference
Berdnikov L N Pis ma Astron Zh
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OBSERVATIONS OF SN ad
Sup ernova SN ad in IC was discovered by Pollas on November
m
Pollas also rep orted the brightness estimate B at discovery date and the
00 00
o sets from the nucleus of the parent galaxy east and south
Sp ectrogram of SN ad was obtained on Nov by Capp ellaro and Della Valle
It showed that SN was of type I I at a very early stage Narrow emission lines of
the Balmer series from H to H sup erimp osed on a very blue continuum were observed
It was also noted that sp ectrum of SN K obtained ten days b efore maximum was
similar to that of SN ad Preliminary photometry gave B B V
V R on Nov UT
Four plates of SN ad were obtained with the cm astrograph at Sternberg As
tronomical Institute Crimean Station The brightness estimates are rep orted in Table I
Table I
Date J D B
Nov
Nov
Nov
Nov
The light curve is shown in Figure We can estimate the date and magnitude of
maximum brightness B on JD November
max
1
According to the RC the parent galaxy type is Sb c the radial velocity v km s
and galactic absorption A As the SN was very blue near maximum the absorp
b
tion in the parent galaxy should b e negligible and we can estimate the absolute magnitude
1 1
at maximum M with H km s Mp c This means that SN ad
B 0
was fainter than SN C and K M but signi cantly brighter than
B
average type I I SNe
The work was partly supp orted by Russian Foundation for Fundamental Research
grants No and by grant No MPP from the International Science Foundation
Figure Light curve of SN ad Dots our data circles data from the literature
D YU TSVETKOV
N N PAVLYUK
Sternberg Astronomical Institute
of Moscow University
Universitetskij Prosp
Moscow Russia
E mail
tsvetkov sai msu su
pavlyuk sai msu su
References
Capp ellaro E Della Valle M IAU Circ No
Pollas C IAU Circ No
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HD AN ECLIPSING MAGNETIC Ap STAR AT LAST
Magnetic Ap stars have a p eculiar distribution of orbital p erio ds when they b elong to
binary systems no magnetic Ap star is known for sure in systems with p erio ds shorter
than days Gerbaldi et al see however the p ossible exception found by North
a This is probably why it is so di cult to nd a single eclipsing binary among
them indeed in spite of some early claims North Renson Mathys Renson
a close examination tends to make these alleged eclipsing Ap stars normal
North a b Ziznovsky
o
We present here a new p ossible candidate the southern star HD CP
was classi ed Ap SiCr p ec by Houk with a quality i e the b est Interestingly
Houk gives a remark saying He is fairly strong with Ca K b eing even stronger yld
A Magnesium may also b e strong Since Ap stars are helium p o or the
strength of He app ears rather strange and implies that this star is unusual even
among the Ap stars
The large amplitude photometric variability was noticed in mid by one of us
CR during the reduction of early data These were gathered at the Europ ean Southern
Observatory La Silla Chile with the double b eam P photometer attached to the
m Swiss telescop e in and systematic monitoring to ok place in June
and July The resulting lightcurves are shown in Figure for the U B
V magnitudes and U B B V colour indices of the Geneva photometric system
according to the ephemeris
HJD Min I E
There is a deep primary minimum while the secondary minimum is very shallow and a
bit ill de ned In V there is a large variation mag outside the eclipses which
is also present in the B band but is less de nite in the U band This out of eclipse
variation resembles the e ect due to the non sphericity of a comp onent nearly lling its
Ro che lob e but such an e ect is not exp ected to b e so wavelength dep endent Moreover
the p erio d is rather long and the primary minimum is short ab out hours suggesting
that the system is well detached Therefore one is tempted to attribute the out of eclipse
variations to the intrinsic variability of the primary which is indeed exp ected to vary
according to its Ap SiCr classi cation But the large scatter in the U band is much
larger than that exp ected from the measurement errors alone mag and suggests
that some irregular phenomena o ccur in this system
Figure Geneva U B and V lightcurves of the eclipsing binary HD
phased according to our ephemeris Notice the large scatter in the U
passband The U B and B V indices are shown as well
1
0.5
6540 6560 6580
Figure High resolution sp ectrum of HD taken at orbital phase
i e at quadrature and showing the star as a double lined system Notice
the asymmetry of the H line of the primary and the emission on
its blue side showing the presence of circumstellar gas
This is con rmed by the U B and B V indices Both minima are clearly visible
showing the secondary to b e redder in B V The b ehaviour of U B in the primary
minimum is quite unexp ected in that the system is b ecoming bluer as the eclipse pro ceeds
while one would exp ect the reverse from the secondary eclipse where the system is at min
imum U B Since the mean values of the reddening free X and Y parameters Cramer
Maeder are and resp ectively we probably have a system comp osed of a
mid B primary and of a late B or early A secondary The mean value of the reddening free
p eculiarity parameter Z is which suggests that one or b oth comp onent s may
have the Si p eculiarity type since this parameter is negative for Bp and Ap stars and null
for normal B and A stars However the mean value of the V G index which is also
a p eculiarity parameter see e g Hauck North is only ab out indicating a
very marginal p eculiarity at most
One of us PN has taken a sp ectrum of this system with the m CAT telescop e
of the Europ ean Southern Observatory equipp ed with the CES sp ectrograph the Long
Camera and the FA CCD detector ESO CCD The resolving p ower was R
The sp ectrum was taken in the H region on the night of May at HJD
i e at phase according to our ephemeris Since this is exactly
at quadrature we can estimate the total mass of the system from the relative velocity at
that phase The sp ectrum displayed in Figure shows however a very p eculiar pro le of
the primary s H line the pro le is not only asymmetric but also shows a blue emission
comp onent Circumstellar gas is therefore certainly present in this system which may
explain the unusual features of the lightcurves
To estimate the relative velocity we rst t a gaussian to the core of the H line of
each comp onent For the primary a large uncertainty results from the asymmetry of the
H line but some con dence interval can b e guessed by tting a gaussian to the whole
pro le on the one hand and to the very core and red side only on the other hand In the
rst case we have A in the second case A The secondary s
p p
line is much more symmetrical and two ts with a slightly di erent tting range give
A and A The range in wavelength di erence is thus
s s
to A corresp onding to a relative velocity V to km s r
Since the eclipses are separated by half a p erio d the assumption of a circular orbit app ears
realistic and we obtain then a semi ma jor axis in the range the inclination i of the orbital
o
plane b eing close to sini is approximated by
a AU
This implies the following range for the total mass
M M M
p s
which is consistent with the sp ectral types estimated ab ove for each comp onent on the
basis of the reddening free X and Y parameters
This system might well b e yet another case of spurious classi cation due to the p e
culiar app earance of an unrecognized comp osite sp ectrum The plate used by Houk for
her classi cation of HD was taken in the night of May i e around
JD which corresp onds to just after the primary minimum But in
view of the uncertainty of the p erio d which is ab out days at most the plate could
have b een taken right in the middle of the primary eclipse and the apparent sp ectrum
would have b een more similar to the intrinsic sp ectrum of the secondary
A complete sp ectroscopic and photometric study would b e needed to clarify the true
nature of this binary
Acknowledgements This work was supp orted in part by the Fonds National de la
Recherche Scienti que Drs N Cramer and M Burnet Geneva and Mr E Paunzen
Vienna contributed to the photometric observations
P NORTH
Institut d Astronomie de l Universit e
de Lausanne
CH Chavannes des Bois
Switzerland
C RICHARD
Observatoire de Gen eve
CH Sauverny Switzerland
References
Cramer N Maeder A A A
Gerbaldi M Flo quet M Hauck B A A
Hauck B North P A A
Houk N Michigan Catalogue of two dimensional spectral Types for the HD Stars
Vol
North P A AS
North P a in The th Workshop and Meeting of European Working Group on
CP Stars I Jankovics I J Vincze eds p
North P b IBVS No
Renson P IBVS No
Renson P IBVS No
Renson P Mathys G IBVS No
Ziznovsky J in Chemically Peculiar Magnetic Stars J Zverko J Ziznovsky
eds p
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January
HU ISSN
A DATABASE OF GALACTIC CLASSICAL CEPHEIDS
We have compiled an electronic database of classical Cepheids in the Galaxy con
tained in four les
DATA KB contains the equatorial and galactic co ordinates The rst POS
of each star taken from the th edition of the General Catalogue of Variable Stars as well
as the HD and SAO catalogue numbers of each star where available
The second le EB V KB is a compilation of ma jor colour excess determina
tions published since
The third PHYSDATA KB lists p erio d intensity mean V magnitude hBi hVi
i i
an adopted E B V the V amplitude hM i distance in parsecs the height from the
v
galactic plane in parsecs mean radial velocity radius from a Baade Wesselink analysis
an indication of binarity and notes relating to double mo de b ehaviour cluster asso ciation
membership etc
MEAN KB gives the V amplitude B amplitude B V The fourth AMP
amplitude hVi hVi hBi hBi h B V i and hBi hVi
mag int mag int mag i i
A fth le having the title of this Bulletin provides background and additional infor
mation on these les This fth le is an ascii le the other four are provided b oth as
ascii les and as dBASE IV binary les
This material is available on the World Wide Web at the URL
http ddo astro utoronto ca cepheids html
and by anonymous ftp at
p erseus astro utoronto ca
in the directory pub cepheids
We would appreciate acknowledgment of your use of these data by reference to this
IBVS announcement Please contact fernie astro utoronto ca in the event of queries
suggestions or di culties
J D FERNIE
Brian BEATTIE
David Dunlap Observatory
David Dunlap Observatory
University of Toronto
University of Toronto
Richmond Hill ON Canada
Richmond Hill ON Canada
L C Y
L C Y
Nancy Remage EVANS
S SEAGER
Physics Astronomy Dept
Harvard Smithsonian CfA
York University
Garden Street
North York ON Canada
Cambridge MA
M J P USA
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SHORT TIME SCALE VARIATION OF " Aur
H BLUE WING EMISSION
Aur is a p eculiar sp ectroscopic binary system with a long p erio d of years Its
primary is an F Ib star around which there is a slowly moving ring like or disk like HI I
radiation cloud accompanying with the rotation of the F star and this makes H wing
pro duce two emission lines with rotating structure The secondary is a disk like multi
ring gaseous cloud Ferluga In eclipse Ferluga and Mangiacapra
observed the shell sp ectra of the secondary and obtained its multi ring mo del
Our observations on Aur H line outside eclipse were carried out by using the
thick CCD system on Coud e sp ectograph of the meter telescop e at Yunnan Observa
tory The disp ersion of the sp ectrograph f is A mm and sp ectral resolution
Read out noise of the CCD system is electrons sec the resolution
of image cell A pixel wavelength range for a single exp osure ab out A and the
signal to noise ratio A line of sight velocity standard star Lep and a sp ec
trophotometric standard star Leo were observed to con rm the H blue wing emission
pro le The measurement errors of the equivalent width values in the H lines are mA
for the absorption and mA for the blue wing emission
In Figure a and b the H observational pro les are given No to No are out
of eclipse H lines of Aur and No is that of the sight line velocity standard star
Lep Two signi cant variations app ear at the blue emission p eaks on No and lines
the emission intensity decreases at the line center and the equivalent widths for these
two lines are mA and mA see Table resp ectively comparing with Nos
and the equivalent width decreases by ab out mA in less than minutes In
the time interval of hr the intensity variation from No to is very small within
mA and on b oth No and lines only a small uctuation app ears in hr p erio d
The variations of the equivalent widths for the blue wing emission and absorption in the
interval of hr on Oct are drawn in Figure It is shown from the ab ove description
that short time scale variations from minutes to several hours exist in the blue wing
emission while the red wing and absorption pro les are similar to previously observed
pro les almost no variation can b e found see Figure a and b The average equivalent
width of the absorption lines is mA only a seventh or eighth of that eclipse the
standard deviation and the maximum variation is within mA smaller than
x
the error of the measurement
From the H observations in Wright and Tan eclipses
in ingress the secondary rst would absorb the H red wing emission and from our mo del
Cha et al the blue wing emission source should b e region C therefore in the re
gion p ossibly exists an HI I cloud with a short time scale variation If our observational
H continuum is taken as a reference in the emission over the continuum in minutes
Figure a
Figure Short time variation of Aur H blue wing emission
Figure b
Figure Short time variation of Aur H blue wing emission
Figure Variation of equivalent widths
interval app ear two fast variations and the intensity ratio is in No and to No
and with the intensity decrease by one third The strong blue wing emission center is
close to the H absorption pro le and active emission may probably lo cate in the region
slowly app earing from the back of the F sup ergiant A continuous monitoring on Aur
is of imp ortance to obtain more information ab out the matter in H rotating ring for
analysing its motion features physical characteristics annd emission mechanism
CHA GUANGWEI
LI YONGSHENG
XU JUN
United Lab oratory for Optical
Astronomy
Chinese Academy of Sciences
Yunnan Observatory
P O Box
Kunming
People s Republic of China
References
Cha Guangwei Tan Huisong Xu Jun and Li Yongsheng A A
Ferluga S A A
Ferluga S and Mangiacapra D A A
Tan Huisong Acta Astrophysica Sinica No
Wright K O and Kushwaha R S Contribution from the Dominion Astrophysical
Observatory No
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HU ISSN
IS TX DELPHINI A POPULATION I CLASSICAL CEPHEID
The pulsating variable TX Del SAO BD is a well known relatively
bright hVi mag Cepheid classi ed as Type I I according to the catalogue of Harris
The classi cation is based on its large distance from the galactic plane z
p c if we assume d kp c distance from the Sun derived from the p erio d luminosity
relation of Type II Cepheids Harris The assumption that TX Del is a classical
Cepheid would result in z kp c Harris Welch This latter z distance
is much larger than the scale height of classical Cepheids p c Fernie Harris
therefore Harris Welch concluded that TX Del is very probably a Type
I I Cepheid
There are some other criteria of the classi cation of Cepheid variables e g metallicity
galactic kinematics light curve shap e etc see Harris and the references therein
The classi cation however has large di culties known for a long time Up to now the
separation based on the z distances seems to b e the most useful and reliable It is
interesting that none of these criteria supp ort the Type I I status of TX Del b ecause it is
a metal rich star among Type I I Cepheids Fe H > according to Meakes et al
and its light curve is very similar to those of classical Cepheids e g Szabados
Recently TX Del has b een discovered to b e a member in a sp ectroscopic binary Harris
Welch separated the pulsational and orbital radial velocities and determined the
orbital parameters of the system
A pro ject of computing physical parameters of metal rich Type I I Cepheids via various
Baade Wesselink techniques has b een started by the authors Unfortunately the number
of stars is quite low due to the lack of precise radial velocity measurements but TX Del is
one of the b est observed ob jects in this sample There are many light curves available and
the precise pulsational velocity curve determined by Harris Welch enabled us to
compute the mean radius with acceptable accuracy The used data are plotted against
phase in Figure
We applied two kinds of techniques deriving the radius the classical Baade Wesselink
metho d based on equal levels of the colour index B V metho d and the surface
brightness metho d based on the Barnes Evans relation and the V R index metho d
0
Both metho ds have lead to very similar results Figure shows the result of veloc
ity curve integration and the computed radii at certain phases using metho d The
physical parameters obtained are tabulated in Table I E B V was adopted from
Meakes et al
Figure Light color and radial velocity curve of TX Del
Figure Radius variation of TX Del during a pulsational cycle The solid curve is
the result of velocity curve integration the lled circles are the radii obtained from the Baade Wesselink solution
Table I
Baade Wesselink parameters and inferred parameters of TX Del
R R B V T K L L M M d p c z p c
0 ef f
The obtained radius of TX Del R R shows that this star is to o large to b e a Type
I I Cepheid The normal radius of an ob ject of this type should b e ab out R which
is considerably smaller Moreover the inferred radius is in very go o d agreement with the
p erio d radius relation for classical Cepheids Gieren Barnes Mo ett Thus it is
probable that TX Del is a Population I classical Cepheid Using this assumption we can
estimate the luminosity and the mass of TX Del as well as its distance from the Sun and
the galactic plane resp ectively These derived parameters are also summarized in Table I
Since TX Del is a member of a binary system the orbital p erio d is quite short P
or b
days it is imp ortant to compare its radius with resp ect to the radius of the Ro che
lob e The mass function of the system is M therefore the minimum mass of the
companion is M The Ro che lobe radius thus b ecomes ab out R so the ratio
of radii R R This value increases up to if the companion is assumed to
star Roche
b e as massive as TX Del
This work was supp orted by the Hungarian OTKA Grant F
Z BALOG and J VINKO
Dept of Optics
JATE University
Szeged D omt er
H Hungary
References
Fernie J D AJ
Gieren W P Barnes T G Mo ett T J ApJ
Harris H C AJ
Harris H C Welch D L AJ
Meakes M Wallerstein G Opalko J F AJ
Szabados L Mitt Sternw Ung Akad Wiss Budapest No
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HU ISSN
DETECTION OF VARIABILITY IN HD
We obtained two nights of di erential photometry of HD and July
The observations were done at the ESO cm telescop e at La Silla The observer
was E Paunzen The measurements are in the Str omgren photometric system and the
integration time was seconds Two comparison stars were observed C HD
m A V and C HD m G IV V Both comparison stars proved to
V V
b e constant within an upp er limit of mag in Str omgren b
The sp ectral type of HD is A I I I I I The following calibrations have b een
adopted by the Str omgrenindices Mo on Dworetsky
T K l og g m
ef f 0
Because of the decreased metallicity and the classi cation as luminosity class I I I I I star
HD is a candidate for the Bo otis group Gray which contains metal weak
A type stars with broad and shallow hydrogen lines the prop erties of this group are
describ ed by Weiss et al Further observations have to prove the membership in
the Bo otis group
Two theories exist concerning the evolutionary status of this group In one case dif
fusion would b e the determining mechanism and the stars are at the end of the ZAMS
phase In the other hypothesis accretion and or mass loss would b e resp onsible for the
low metallicity and the stars are just arriving at the ZAMS
The to ols of asteroseismology should make it p ossible to determine the p osition of stars
within the HR diagram We started therefore a survey for p erio dic variability among
Bo otis stars Up to now we found new pulsating stars For HD the maximum
p eak in the frequency sp ectrum app ears at f c d P minutes with a semi
amplitude of mag in Str omgren b see Figure This p erio d is consistent with an
exp ected p erio d of an A type star at the ZAMS Stellingwerf Figure shows
the light curve for the rst night for all three measured stars All light curves are in
instrumental magnitudes with an o set
This amplitude sp ectrum gives some evidence for the presence of more than one pul
sation frequency In spite of the rather p o or quality of b oth nights the variability of HD
seems to b e well established Further observations have to improve the rep orted results
Figure The light curve for HD upp er panel C middle panel
and C lower panel for the rst night in Str omgren b
Figure Amplitude sp ectrum for the di erential data
of HD and HD
Figure Sp ectral window for the di erential data
of HD and HD
Acknowledgement This research was supp orted by the Ho chschuljubil aumsstiftung
der Stadt Wien
E PAUNZEN
U HEITER
W W WEISS
Institut f ur Astronomie
T urkenschanzstr
A Wien Austria
E mail PAUNZEN ASTRO AST UNIVIE AC AT
References
Gray R O Precision Photometry ed A G Davis Philip A R Upgren K A
Janes L Davis Press Schenectady N Y p
Mo on T T Dworetsky M M MNRAS
Stellingwerf R ApJ
Weiss W W Paunzen E Kuschnig R Schneider H A A
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HU ISSN
OBSERVATIONS OF SUPERHUMPS IN V Cyg
DURING THE SUPEROUTBURST
Variability V Cyg was discovered by Weber who rep orted an outburst
o ccurred in Rather rapid decline resembles that of a fast nova but the nature and
the identi cation in quiescent state has remained uncertain for a long time Systematic
visual monitoring of this variable star by amateur astronomers started in the s After
a long series of negative observations the star was nally caught in its second historical
outburst by M Moriyama on Oct UT at m and by P Schmeer on
v
Oct UT at m Moriyama and Schmeer Korth The
v
outburst was subsequently con rmed by CCD observation by the author on Oct The
ob ject was rst observed in BVI bands Its conspicuous blue color made the dwarf nova
classi cation most likely
Following this con rmation the author obtained a time resolved V band CCD photom
etry of this ob ject on eight nights b etween Oct and Nov The observations were
carried out using a cm re ector and a Thomson TH chip pixels at Ouda
Station Department of Astronomy Kyoto University for a description of the instruments
see Ohtani et al The exp osure time was b etween and s dep ending up on
the brightness of the variable The frames were rst corrected for standard de biasing
and at elding and were then pro cessed by a micro computer based automatic ap erture
photometry package developed by the author The di erential magnitudes of the vari
h m s 0 00
ables were determined using a lo cal standard star : : J
V the p osition and the magnitude from the Guide Star Catalog whose constancy
was con rmed using several check stars in the same eld The estimated error of single
observation is mag under favorable condition
The overall light curve for the outburst is given in Figure which shows a smo oth
slow decline followed by a rapid return to quiescence From the time resolved photometry
clear sup erhumps with a mean amplitude of mag were detected on Nov see
Figure this observation revealed the SU UMa type nature of this ob ject Kato
Twelve sup erhump maxima were observed b etween Nov and and by linear regression
of the sup erhump times we could obtain a sup erhump p erio d of day A p erio d
analysis using the phase disp ersion minimization PDM metho d Stellingwerf after
removing the steady decline yielded the b est estimate of the sup erhump p erio d of
day An examination of a rather fragmentary light curve on Oct could reveal
only mag variation Figure which could not t the ab ove sup erhump p erio d An
examination of an image on Nov taken at the exp ected sup erhump maximum again
failed to show a large amplitude mag variation against the rest of the images
taken on the same night From these ndings we concluded that the full development of
the sup erhumps in this ob ject to ok days from the outburst maximum This value
is much longer than days in typical SU UMa stars
Figure General V band light curve of V Cyg The
zero p oint of the relative magnitudes corresp onds to V
Figure Light curve for nights from Nov through Nov The magnitude
is o set by mag for each night Sup erhumps are clearly seen
Figure Light curve on Oct Only a small
amplitude mag variation was present The large
scatter is due to the unfavorable sky condition
The star has b een monitored since and was recorded again in sup eroutburst on
Dec Schmeer et al Apparent absence of normal outbursts b etween these
two sup eroutbursts rarity of outbursts from a search in archival plates Wenzel
the long interval years b etween the two successive sup eroutburst a large outburst
amplitude mag and the slow development of sup erhumps all make V Cyg
a close relative of WZ Sge stars Bailey Downes or TOADs Tremendous
Outburst Amplitude Dwarf Novae Howell All the characteristics of V Cyg
most resemble those of SW UMa despite the fact that V Cyg has a much longer
sup erhump p erio d
The author would like to p oint out one more p eculiar feature in the light curve Al
though one should b e careful in comparing the visual and CCD magnitudes the available
material shows that this dwarf nova showed a rapid initial decline from m Oct
v
to Oct this study The similar feature can b e also found in the light curve by
Weber This feature would b e explained in the scheme of disk instability mo del
by the extra mass accumulated in the accretion disk during quiescence in the absence of
normal outbursts Osaki and would b e a clue to understanding the p eculiar out
burst pattern of WZ Sge stars A search for normal outbursts and detailed observations
of V Cyg b oth during outburst and quiescence are therefore highly encouraged
The authors are grateful to M Moriyama VSOLJ and P Schmeer for promptly
notifying us of the outburst and providing the visual estimates Part of this work is
supp orted by a Research Fellowship of the Japan So ciety for the Promotion of Science for
Young Scientists
Taichi KATO
Dept of Astron Faculty of Sci
Kyoto University
Sakyo ku Kyoto Japan
References
Bailey J MNRAS P
Downes R A AJ
Howell S B in Cataclysmic Variables and Related Physics ed O Regev G Shaviv
Annals of the Israel Physical So ciety Vol p
Kato T IAU Circ No
Korth S Moriyama M Schmeer P IAU Circ No
Moriyama M and Schmeer P IAU Circ No
Ohtani H Uesugi A Tomita Y Yoshida M Kosugi G Noumaru J Araya S Ohta
K et al Memoirs of the Faculty of Science Kyoto University Series A of
Physics Astrophysics Geophysics and Chemistry
Osaki Y in Theory of Accretion Disks ed W J Duschl J Frank F Meyer
E Meyer Hofmeister W M Tscharnuter Kluwer Academic Publishers Dordrecht
Schmeer P Szentasko L and Manning B IAU Circ No
Stellingwerf R F ApJ
Weber R IBVS No
Wenzel W IBVS No
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January
HU ISSN
PHOTOELECTRIC OBSERVATIONS OF THE ECLIPSING
VARIABLE DO Cas
During the observational season we turned our attention to the eclipsing variable
star DO Cas SAO in order to check the correctness of the ephemeris rep orted in
the literature and to obtain the entire light curve
The photo electric observations were carried out at the station of Capanne di Cosola
AL Italy for six nights spanning from August to September collecting a total
of p oints in the instrumental V lter The adopted photometric device was an
OPTEC SSP photo electric photometer sp ectral sensitivity S attached to a mm
Schmidt Cassegrain f telescop e The integration time was xed to ten seconds p er count
The adopted comparison star was HIC SAO the check one was HD
SAO The data of the involved stars are listed in the Table
We obtained helio centric times of minimum two primary and two secondary ones
listed in Table These moments of minimum have b een obtained pro cessing the data
by the Minimum Entropy SOP pro cedure MEMSOP Gaspani Table shows the
residuals computed with resp ect to the following ephemeris
d
Min I J D hel : E
listed by the General Catalogue of Variable Stars Kholop ov et al The values
of the residuals suggest that the ephemeris listed ab ove is still valid the phase curve
obtained using this ephemeris is shown in Figure
In order to recover a convenient estimate of the true signal from the noisy phased data
we pro cessed them by a signal recovery technique based on an arti cial neural network
implementing a multilayer p erceptron according to Haykin Masters and
others The restored signal is graphed as a solid line across the original data p oints
in Figure The at secondary minimum is well evident A further analysis of our
observations in view to solving the light curve and determining the orbital parameters of
the binary system is in progress
Table Data of the involved stars
RA Decl V B V Sp
h m s
DO Cas HIC BD A V
HD SAO
h m s
HIC BD F I I I
HD SAO
h m s
HD SAO A Ib
Figure Photo electric observations of DO Cas op en squares The
solid line is the signal restored by neuro computing techniques
Table Observed times of minimum
Date Ep o ch Times of minimum Residual Type
E Helio centric J D O C
Aug I
Sep II
Sep I
Sep II
Marco ALUIGI
Gianni GALLI
GEOS Promenade Venezia
GEOS Promenade Venezia
F Versailles France
F Versailles France
Adriano GASPANI
Osservatorio Astronomico di Brera
Via Brera Milano Italy
and
GEOS Promenade Venezia
F Versailles France
e mail gaspani bach mi astro it
References
Kholop ov et al General Catalogue of Variable Stars GCVS Moscow
Gaspani A The algorithms useful in nding the extrema of the light curves
Final Rep ort of the Second GEOS Workshop on the Eclipsing Variable Stars and
their Data Pro cessing S Pellegrino Terme Italy May
Haykin S Neural Networks A Comprehensive Foundation Macmillan College
Publishing Company Inc p
Masters T Signal and Image Pro cessing with Neural Networks J Wiley New York
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
January
HU ISSN
PHOTOELECTRIC UBVR OBSERVATIONS
OF THE PECULIAR CEPHEID RU Cam
It is well known that RU Cam is a Cepheid with irregularly variable amplitude Koll ath
and Szeidl
We observed RU Cam at the Mt Maidanak observatory in September Octob er
The cm re ector was used and UBVR measurements were obtained Table the
c
accuracy of the individual data is near mag in all lters According to our data the
amplitude of light curve Fig is near mag
The phases are calculated with the elements
M axJ D hel E
This study was partially supp orted by the Russian Foundation for Fundamental Re
search through grants No and No
Table
JD hel Phase V U B B V V R
c
Figure
L N BERDNIKOV
O V VOZIAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
Reference
Koll athZ Szeidl B Astron Astrophys
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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February
HU ISSN
DISCOVERY OF THE SECOND PG TYPE
DWARF NOVA V Ori
This star was discovered to b e variable by Wolf and Wolf called and
then suggested by Kipp enhahn to b e a p ossible member of U Gem stars In the
New Catalogue of Susp ected Variable Stars Kukarkin et al it was designated as
NSV with a brightness range of m The subsequent photographic
pg
observation by Natsvlishvili revealed that its magnitude varied from at max
th
imum to at maximum and it was nally named V Ori of INS type in the
namelist of variable stars Kholop ov et al
Jablonsky and Cieslinski made sp ectroscopic and photometric observations and
prop osed its orbital p erio d of days which suggests that V Ori
is a go o d candidate for an SU UMa star Their observations however could not reveal
sup eroutbursts or sup erhumps exp ected for this class of CVs The p eculiar nature of
V Ori was already suggested by their estimate of short outburst cycle length of
days together with its small outburst amplitude VSOLJ Variable Star Observers League
in Japan started CCD and visual observations part of which was published by Kiyota
These observations indicated presence of bright reaching m outbursts
V
some of which b ore the characteristics of sup eroutbursts
The present outburst of V Ori was rst detected by the Rob oScop e Indiana
University Automated Photometric Telescope Honeycutt and Turner It was inde
p endently discovered on Dec at m by M Yamada VSOLJ private communi
V
cation We made photometric observations on Dec and using CCD camera
Thomson TH CDA pixels with m square pixel size attached to the
Cassegrain fo cus of m re ector with Johnson V band lter at the Ouda Station Kyoto
University Ohtani et al The mo de of on chip summation was employed
A total of frames were taken b etween and UT under clear sky and
frames b etween and UT interrupted for minutes by clouds The exp osure
time was seconds on Dec and varied b etween and seconds on Dec
We reduced the data using the p ersonal computer based ap erture photometry package
developed by one of the authors T K This package automatically subtracts bias frames
applies at elding and enables us to estimate the instrumental magnitudes The ap erture
size was in radius The sky level was determined from pixels whose distance from the
individual ob jects are b etween to
Figure V band light curve of V Ori on Dec
The zero p oint of the relative magnitudes corresp onds to V
Figure The theta diagram by PDM on the
data of V Ori on Dec and
Figure shows the light curve of di erential magnitude b etween V Ori and a
comparison star on Dec The comparison star is c in Jablonsky and Cieslinski
whose V magnitude is given as in thier Table A decay of amplitude of
humps is seen in the gure and the similar mo dulation was also observed in PG
Nogami et al We analysed the light curve using phase disp ersion minimization
PDM metho d Stellingwerf implemented in IRAF package IRAF is distributed
by National Optical Astronomy Observatories U S A Figure shows the diagram
1
whose abscissa is frequency day The lowest minimum p oint in corresp onds to
days Rob ertson et al indep endently detected the same hump features
and rep orted that they are rep eated with a p erio d of days
The di erence in the photometric and sp ectroscopic p erio ds con rmed the sup erhump
nature of these humps The outburst observed by Jablonsky and Cieslinski did not
show sup erhump like mo dulation and corresp onds to normal outburst of usual SU UMa
stars Thus V Ori was unambiguously identi ed to b e an SU UMa type dwarf nova
with a sup erhump p erio d of days The present discovery of sup erhumps
in V Ori together with its extreme shortness of its outburst recurrence time its
long duty cycle Jablonsky and Cieslinski Kiyota and its extremely short
sup ercycle recurrence time of sup eroutbursts Rob ertson et al has established
a new subgroup of p eculiar dwarf novae whose prototype is PG Kato and
Kunjaya Misselt and Shafter Osaki
The fact that the sup ercycle of V Ori days Rob ertson et al is almost
equal to that of PG days is p ossibly not accidental According to Osaki
the shortest sup ercycle predicted by disk instability theory under a given strength
of the tidal torques is ab out days and the sup ercycle is insensitive to the mass transfer
rate from the secondary around this minimum value However as rst p ointed out in
the case of PG by Kato and Kunjaya and later con rmed by numerical
simulation by Osaki a dwarf nova with minimum sup ercycle length should have
much ten times larger mass transfer rate than those of usual SU UMa type dwarf
novae near the b orderline b etween nova like stars and SU UMa type dwarf novae For a
dwarf nova with an orbital p erio d b elow the p erio d gap it is generally b elieved that its
mass transfer is p owered by the gravitational wave radiation that is its rate is mainly
dep endent on the orbital p erio d The shortness of the orbital p erio d of V Ori
days Jablonsky and Cieslinski and the sup erhump p erio d of PG
days Kato and Kunjaya implies small mass transfer rates in the present scheme of
CVs which are clearly in con ict with such large mass transfer rate exp ected from their
outburst b ehavior
The present discovery of another PG star suggests that this type of CVs
may not considered to b e unique but form a larger p opulation in CVs than ever exp ected
In this case the present picture of the mechanism of mass transfer and the evolution of
CVs b elow the p erio d gap would unavoidably b e mo di ed
The authors are grateful to the VSOLJ Variable Stars Observers League in Japan
members for supplying us of visual and CCD estimates and esp ecially M Yamada for
notifying us of the outburst Thanks also to Y Osaki K A Misselt and R K Honeycutt
for sending us their preprints We acknowledge R K Honeycutt for op ening the real
time light curve by Rob oScop e to public through the World Wide Web This research has
b een partly supp orted by Research Fellowship of the Japan So ciety for the Promotion of
Science for Young Scientists T K
Daisaku NOGAMI
Taichi KATO
Seiji MASUDA
Ryuko HIRATA
Dept Astron Faculty of Sci
Kyoto University
Oiwake cho Kitashirakawa
Sakyo ku Kyto Japan
References
Honeycutt R K and Turner G W in Robotic Telescopes in the s ed A
Filipp enko San Francisco ASP
Jablonsky F J and Cieslinski D Astron Astrophys
Kato T and Kunjaya K Publ Astron Soc Japan in press
Kholop ov P N Samus N N Kazarovets E V and Kireeva N N Inf Bul l
Var Stars No
Kipp enhahn R Astron Nachr H
Kiyota S in Variable Stars in Japanese Japan Variable Star Study Asso ciation
Vol
Kukarkin B V et al in New Catalogue of Suspected Variable Stars ed P N
Kholop ov Nauka Publishing House Moscow
Misselt K A and Shafter A W Astron J in press
Natsvlishvili R Sh Inf Bul l Var Stars No
Nogami D Kato T Masuda S and Hirata R in preparation
Ohtani H Uesugi A Tomita Y Yoshida M Kosugi G Noumaru J Araya S
Ohta K Memoirs of the Faculty of Science Kyoto University Series A of
Physics Astrophysics Geophysics and Chemistry
Osaki Y Publ Astron Soc in Japan in press
Rob ertson J W Honeycutt R K and Turner G W Publ Astron Soc Paci c
submitted
Stellingwerf R F Astrophys J
Wolf M and Wolf G Astron Nachr
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
February
HU ISSN
U FILTER PHOTOMETRY OF AB DORADUS
AB Doradus HD is a rapidly rotating day late type star K IV V
in the solar neighborho o d at a distance of ab out p c The rapid rotation is due to its
youth as indicated by the presence of strong lithium absorption Rucinski The
star apparently b elongs to the Pleiades moving group Innis et al It is a very
active star one of the most active presently known Several investigations of di erent
asp ects of its activity have b een cited in pap ers by Vilhu et al and by Lim
et al
The great imp ortance of this star resulted in the award of a substantial amount of
observing time of the Space Telescope for sp ectral monitoring of selected UV sp ectral re
gions with the Go ddard High Resolution Sp ectrograph The two adjacent HST programs
conducted on November were led by the Principal Investigators F Walter
and O Vilhu In addition simultaneous optical sp ectroscopy was obtained from CTIO as
were simultaneous observations with the EUVE and ROSAT The present note describ es
photometric supp ort monitoring of AB Dor p erformed on two nights and
November with the Helen Sawyer Hogg cm telescop e of the University of Toronto
at Las Campanas These observations were meant as a check of the star s aring activity
Also since X ray and EUV satellites have relatively low spatial resolution p ossible ares
of the optical companion of AB Dor Rst B could contaminate the high energy data
Our observations could b e used to monitor and detect strong ares of Rst B
The photometric monitoring was done with a CCD camera Photometrics
00
pixels p er pixel and with a xed U band lter of the UBV set The exp osures
of the variable were seconds long and they were done in as rapid succession as was
practicable given the relatively long readout time The e ective sampling was thus typ
ically one frame p er minute The UT time was recorded manually with an uncertainty
of ab out seconds Every minutes the comparison star HD was observed
The photometric data have b een extracted from the CCD images using simple ap erture
photometry The nal results are in instrumental magnitude di erences u in the sense
AB Dor minus HD In addition to AB Dor several observations of the second
comparison HD were obtained each night They gave the mean di erences u
b etween the two comparison stars HD HD equal to and
for each night resp ectively
The results for AB Dor are displayed in graphical form as a function of the helio centric
Universal Time expressed in fraction of Julian Day in the accompanying gure The basic results are
The U lter di erential light curves of AB Dor obtained
on nights and November at Las Campanas
A well de ned sp ot mo dulation with U ' was observed over basically the
same rotation phase window ab out of full rotation on b oth nights The wave
minima were lo cated approximately at JD and JD
The minima corresp ond to phase of the ephemeris given by Innis et al
JD min E Minima placed at that phase could b e ex
plained by a feature designated Sp ot B by Innis et al
Assuming that U for HD Cutisp oto Ro don o and that our
instrumental system U is the same as the standard one which we cannot con rm we
observed variability of AB Dor b etween approximately U Assuming
further that AB Dor has typically U V ' the corresp onding visual range was
V This would indicate that the star is still faint and that a brightening
trend of the sp ot cycle whose rst signs were rep orted by Anders has not yet fully taken place
No are activity of any imp ortance was noted During the second night low level
activity might have b een present during the ascending branch of the sp ot wave
The visual companion of AB Dor was not observed in any of the CCD images
Because our system had low sensitivity in U and exp osures were short the detection
limit for Rst B was at relatively high brightness ab out magnitudes b elow
that of AB Dor i e at ab out U ' Rst B is a faint V ' M dwarf
Vilhu et al with unknown probably very low brightness in ultraviolet Thus
we could detect only the largest ares from this star
The tabular data with our observations of AB Dor is available from the authors at the
following e mail addresses rucinski astro utoronto ca or garrison astro utoronto ca
This research has b een supp orted by the Natural Sciences and Engineering Research
Council of Canada through op erating grants to Garrison and Rucinski
Slavek RUCINSKI
R F GARRISON
Boyd DUFFEE
David Dunlap Observatory
P O Box
Richmond Hill Ontario
Canada L C Y
References
Anders G J IBVS No
Cutisp oto G Ro don o M IBVS No
Innis J L Thompson K Coates D W MNRAS
Innis J L Thompson K Coates D W Evans T L MNRAS
Lim J Nelson G J Castro C Kilkenny D van Wyk F ApJ L
Rucinski S M MNRAS
Vilhu O Gustafsson B Edvardson B ApJ
Vilhu O Ambruster C W Ne J E Linsky J L Brandenburg A Ilyinn I V
Shakhovskaya N I A A
Vilhu O Tsuru T Collier Cameron A Budding E Banks T Slee B Ehrenfreund
P Foing B H A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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February
HU ISSN
PHOTOMETRIC OBSERVATIONS OF ECLIPSES IN
THE SYMBIOTIC TRIPLE SYSTEM CH CYGNI
CH Cygni is probably the most p eculiar ob ject among all known symbiotic stars The
complex b ehaviour of the sp ectrophotometric parameters and the light curve observed
during the outbursts led at rst to a single star mo del
e g Faraggiana Hack The binary nature of CH Cyg was suggested by radial
velocity measurements in the optical sp ectrum for b oth comp onents e g Yamashita
Maehara Tomov Luud and by the eclipse of the hot comp onent by the
red giant observed during May Octob er e g Miko lajewski et al CH Cyg
then was accepted as the symbiotic binary with the long day p erio d orbit Recently
Hinkle et al analysing a year time series of high resolution m infrared sp ectra
of CH Cyg found a very regular variation in the red giant radial velocities with a day
p erio d They suggested that CH Cyg is a triple system with the symbiotic pair b eing the
short day p erio d system while the unseen G K dwarf revolves around the symbiotic
binary in the long year p erio d orbit However they state that CH Cyg cannot b e an
eclipsing system and the orbital inclination must b e The aim of this contribution
is to present our new photometry showing that CH Cyg really is an eclipsing symbiotic
triple system
CH Cyg has b een regularly monitored at the Skalnat e Pleso m ab ove the sea
level and Star a Lesn a our down station near Tatransk a Lomnica observatories
The observations have b een made in the standard UBV system using a one channel photo
electric photometer installed in the Cassegrain fo cus of the m re ectors The stars
HD V B V U B and SAO m m
v pg
sp ectrum F were used as the comparison and the check stars resp ectively
In Figure we show the historical U light curve as this represents b est b ehaviour in
the blue continuum of CH Cyg during outbursts quiescence as well as eclipses Our new
data observed up to January are displayed in more detail in Figure together
with those published by Panov Ivanova and Leedj arv It covers the
p erio d of the current outburst which b egan at the b eginning of Skopal et al
During this active phase photometric observations indicate the two deep minima of ab out
and mag in the U band resp ectively and times of their centres at JD
and JD Other such minima o ccurred during the active phase at
JD and JD Positions of these four minima agree well with times
of the sp ectroscopic conjunction of the symbiotic pair co ol comp onent in front in the
triple star mo del of CH Cyg T JD P day circular orbit
conj orb
derived by Hinkle et al Thus we can conclude that these minima are caused by
the eclipse of the active comp onent by the co ol comp onent in the short period symbiotic pair
Figure Historical U light curve for CH Cyg Eclipses
in b oth the long and short p erio d orbit are marked
Figure The UBV light curves of CH Cyg covering the current outburst
The minima corresp ond to the eclipses of the active comp onent
by the co ol comp onent in the day p erio d symbiotic pair
During the and quiescent p erio ds due to a very low level of the
blue continuum the eclipses could not b e detected Nor were they present in the light
curve during the last active phase Due to a very high level of activity during
that p erio d the circumstellar matter in the symbiotic pair was probably lo cated within
the common p otentials of the binary and that way instead of deep and relatively narrow
minima we observed a rather complex wave like variation in the light curve cf Figure
On the other hand the p erio dic day variation in the U B V light curves cf
Skopal at a level of ab out mag and with minima at the sp ectroscopic conjunction
observed during the quiescent p erio ds resembles that present in light curves of the other
classical symbiotic stars e g AG Peg V Her AG Dra EG And
In addition the historical light curve exhibits two more minima in the U band at
JD and JD Their p ositions agree p erfectly with times of the
sp ectroscopic conjunction in the long period orbit T JD P
conj orb
days e Hinkle et al Bearing in mind the very large
separation of the comp onents in the long p erio d orbit approximately of R and
the radius of the giant to b e of to R the orbit inclination must b e very high
to pro duce the observed shap e of the minima mainly that in A rough estimation
gives i
The agreement b etween the p ositions of the minima observed in the U light curve and
times of the sp ectroscopic conjunctions for b oth orbits allow us to conclude that CH Cyg
is an eclipsing symbiotic triple system
A SKOPAL
Astronomical Institute
Slovak Academy of Sciences
Tatransk a Lomnica
Slovakia
References
Faraggiana R Hack M A A
Hinkle K H Fekel F C Johnson D S Scharlach W W G AJ
Leedj arvL IBVS No
Miko lajewski M Tomov T Miko lajewska J Ap SS
Panov K P Ivanova M S IBVS No
Skopal A Hric L Kom z kR IAU Circ
Skopal A Contrib Astron Obs Skalnat e Pleso
Tomov T Luud L Afz
Yamashita Y Maehara H PASJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
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February
HU ISSN
THE DISCOVERY OF H EMISSION IN V Cas
d
The eclipsing binary star V Cas HD V V P : B I I
B I I I is a relatively p o orly investigated ob ject Hill and Fisher studied the orbit
and physical parameters of V Cas They used their high S N ratio sp ectroscopic ob
servations in the blue sp ectral region and incomplete light curve showing large distortion
obtained by Lynds We included V Cas in our program of the double B stars
with purp ose to determine its evolutionary status atmospheric parameters helium abun
dance and matter ows The results of these complex investigations will b e published
later and now we rep ort the discovery of emission in H and HeI lines and its
variability during the orbital p erio d
Our sp ectral photometric and p olarimetric observations were carried out during
The sp ectral data were obtained using coud e sp ectrograph with GEC CCD of the m
telescop e of Crimean Astrophysical Observatory The sp ectral resolution were and
for H and HeI resp ectively The S N ratio was The photometric and
p olarimetric data were obtained at the m telescop e with the UBVRI ve channel
photometer p olarimeter
Figures and illustrate some of typical pro les of HeI and H lines for the di erent
orbital phases The phases ' have b een calculated according to the ephemeris of Hill
and Fisher From Fig one can see that the primary the more massive star
A and the secondary the less massive star B HeI comp onents were observed near the
elongations ' and ' One should pay attention to the weak red emission
comp onent in HeI pro le at the phase Fig From Fig one can see that the H
pro le has a more comp osite structure there are absorption and emission comp onents
and they are variable during the orbital p erio d The H pro le has b een observed by us
and by Hill and Fisher but no emission was found in this line The presence of the
emission may b e considered as an evidence of the mass exchange b etween the comp onents
and it is more probably that the matter out ows from the primary Our considerations
are similar to those of Hill and Fisher namely the primary comp onent is close to
or at the Ro che lob e at p eriastron and there is non synchronism for b oth comp onents
m
Our photometric observations have shown the low amplitude variability : in all
ve passbands We also found the unexp ectedly large phase lo cked p olarimetric
variability which may b e considered as an additional evidence for the existence of the
circumstellar gas
We hop e that our complex observations of V Cas together with the earlier results
of the other authors will allow us to understand b etter the nature of the binaries which
are on the short duration stage of the mass loss from more massive primary
Figure HeI line pro les
Figure H line pro les The sharp absorptions are the telluric H O lines
2
This research was made p ossible in part by grant U C from the International Sci
ence Foundation
A V BERDYUGIN
T M RACHKOVSKAJA
S I ROSTOPCHIN
A E TARASOV
Crimean Astrophysical Observatory
p Nauchny Crimea Ukraine
e mail rtm crao crimea ua
References
Hill G Fisher W A Astron Astrophys
Lynds C R Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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February
HU ISSN
A POSSIBLE VARIABLE STAR RECLASSIFICATION FOR TX PISCIUM
From through the Lb Kholop ov carb on star TX Piscium has b een
observed via photo electric photometry as part of the AAVSO Small Amplitude Red Vari
able SARV program The ob jective was to discover p erio dicity if any and re ne existing
measured amplitudes Wasatonic rep orted the rst evidence of semi regularity in
visual light with well de ned amplitudes This pap er presents observations taken since
to show further evidence of semi regularity which is used as the basis for variable star
reclassi cation no existing light curves have b een found to back up the Lb classi cation
A SIMBAD database search yielded references of this highly observed star most
of them describing sp ectroscopic work Various sp ectral types have b een published C
Judge and Stencel N C Barnbaum or C II Ho eit and
Richer In general carb on stars are p eculiar red giants their sp ectra are charac
terized by bands of carb on containing molecules in contrast to normal K and M sp ectra
where oxides predominate Faulkner et al A more thorough discussion of carb on
star sp ectral characteristics is b eyond the scop e of this pap er and will not b e addressed
further
All observations were made with a inch f Schmidt Cassegrain and a silicon PIN
photo dio de SSP photo electric photometer using a Schott visual lter Standard photo
metric observations and data reduction techniques were used as describ ed in the earlier
pap er by the author The observations were made on separate nights from JD
to JD The maximum internal standard error calculated for each night was
millimags the internal standard average error over all nights was only millimags
It is prop osed that the variable star classi cation for TX Piscium b e changed from its
current Lb type to that of a semi regular variable of type SRa or SRb The scienti c
justi cation of this reclassi cation is as follows
From SiO and H O maser observations it is sp eculated that the circumstellar enve
lop e surrounding the star is clumpy in nature and is not con ned to a region close to
the star Heske et al This theory is supp orted to some degree by Judge and
Stencel in which they state that TX Piscium as an optically visible carb on
star is thought to b e in a p ost Mira evolutionary phase in this phase there exists
a circumstellar shell which has b ecome detached from the star Heske also states
that since the detached circumstellar shell is irregular clumpy mass loss is asym
metric which can b e caused by pulsational prop erties of SR variables Heske also
states that TX Piscium is classi ed as an SR variable by referencing Kukarkin et al
Figure
Alksne et al classify the sp ectrum as C according to this data distribution
TX Piscium would b e an Lb variable However most literature references classify the
sp ectrum as either C or C I I This would indicate an SR type variability according
to Alksne s data distribution and again matches the prop osed reclassi cation type
An examination of the light curve itself reveals semiregularity see Figure Table
I lists the observed times of minima and the intervals b etween them The last three
intervals are actually times separated by two non consecutive minima as the missing
minima are due to seasonal gaps Hence the average time b etween all minima is ab out
days
Table I TX Piscium Minima Data
Times of Minima Intervals Between Minima Days
JD
JD
JD
JD
JD
Table I I TX Piscium Maxima Data
Times of Maxima Intervals Between Maxima Days
JD
JD
JD
JD
Table I I I TX Piscium Visual Light Curve Data
JD MAG JD MAG JD MAG JD MAG
Table I I lists the observed time of maxima and the intervals b etween them Again the
last two intervals are actually times b etween two non consecutive maxima missing
again due to seasonal gaps Hence the average time b etween all maxima is ab out
days which nearly matches the minima interval Therefore one can deduce a
semi regular p erio d averaging days
Since SRa variables have relatively constant p erio ds smaller amplitudes than Miras
< mag and strong cycle to cycle amplitude variations Querci and Querci
it is apparent that the published light curve ts these characteristics to some
degree Hence these features lend credence to re classifying TX Piscium as an SRa
variable star
A distribution of semi regular p erio ds was done by Petit and for SRb stars of
sp ectral type C and S there is a mo dal value at p erio ds b etween and days
the apparent day p erio d falls within this range Additionally the light curve
asymmetry is typical for SRa stars with p ossible extensions to SRb stars
Hence these features supp ort a SRb classi cation
One can also see the sup erp osition of a cycle on top of the day principle cycle by
noting the gradual rise and decline of each seasonal variation with the p eak o ccurring
from JD to JD This second cycle is a characteristic feature of SRb
stars Petit A preliminary cycle of days can b e measured from the
minimum at JD to the minimum at JD This is ab out times
the principle cycle but still less than the normal mo dulation of to years for SRb
stars Further observations are required to characterize this phenomenon
In researching published amplitude ranges Drake et al and Judge and Stencel
rep orted an amplitude range of mag somewhat more than the maximum
observed amplitude of mag Mitton and MacRob ert also rep orted a total
amplitude of mag Because the total amplitude for the seasonal cycles averaged
mag p erhaps the Mitton and MacRob ert amplitude is a feature of the sup erp osition
cycle It now app ears that the rep orted mag amplitude is erroneous and could b e
due mainly to scattered results
Concluding based on the visual light curve and supp orting arguments the classi ca
tion of TX Piscium should b e changed from an irregular Lb giant to an SRa or SRb giant
Due to the nature of red giants more observations could reveal a presumed resumption
of irregularity for this reason and to further de ne the sup erp osition cycle observations
will continue inde nitely Nevertheless in visual light TX Piscium is now pulsating with
characteristics of a semi regular star and thus its classi cation should b e made accord
ingly so
Rick WASATONIC
Computer Sciences Corp oration
IUE Observatory
A Aerospace Road
Lanham Seabro ok
Maryland USA
References
Alksne Z K Alksnis A K Dzervitis U K Prop erties of Galactic Carb on Stars
Orbit Bo ok Company Inc
Barnbaum C AJ
Drake S A et al AJ
Faulkner D R Honeycutt R K Johnson H R ApJ
Heske A Te Lintel Hekkert P Maloney P R A A L
Ho eit D Yale Bright Star Catalog th Edition Yale University Observatory
Judge P G Stencel R E ApJ
Kholop ov P N GCVS th Edition Moscow
Kukarkin B V et al GCVS rd Edition Moscow
Mitton J MacRob ert A Sky and Telescope
Petit M Variable Stars Wiley and Sons Ltd
Querci M Querci F in Evolution of Peculiar Red Giant Stars eds Johnson H R
and Zuckerman B pg
Richer H B ApJ
Wasatonic R Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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February
HU ISSN
SOLAR MAGNETIC FIELD MODULATION OF THE NEUTRINO FLUX
So on after the rst neutrino observations had b een published it b ecame clear that the
solar neutrino ux was not only much smaller than exp ected from the solar standard
mo del the rst neutrino problem It also proved to b e variable in time the second
neutrino problem which implied that the Sun was a variable neutrino star For more
detail see Bahcall Rivin and references therein
Time uctuations of the solar neutrino are not quite understo o d Some authors b elieve
them asso ciated with solar activity whose growth results in a decreased neutrino ux
37
Ar measurements at South Dakota i e a negative correlation with the solar activity
indices is supp osed Voloshin et al Rivin According to this hypothesis
the neutrino ux passing through a strong magnetic eld is mo dulated as part of the
left hand neutrino are transformed into the right hand neutrino The mo dulation mainly
dep ends on two factors the magnetic moment of the neutrino and the absolute value of the
transverse magnetic eld comp onent This mo dulation is di cult to obtain in lab oratory
However there is evidence indicating that it o ccurs in the Sun as the high energy neutrino
ux from the core passes through the magnetic eld in the solar convection zone
To verify this hypothesis it is essential to choose an index that would characterize
most adequately the magnetic eld in the solar interior along the neutrino propagation
line Such indices used in early work are the Wolf number or the mean photospheric
eld However b oth of them are dissatisfactory as they are global indices We have used
magnetic eld measured every day from the Zeeman e ect at intersection of the solar
center Earth line with the photosphere The data were obtained at the John Wilcox
Observatory of the Stanford University WSO These observations started in May
Carrington rotation and the data are available up to inclusive Ho eksema
and Scherrer Ho eksema The earlier p erio d since is covered by the
data obtained at the Mount Wilson Observatory MWO by Rob ert Howard s group and
kindly placed at our disp osal by J Sten o Both data series are used in our analysis in
spite of some nonuniformity
These measurements based on p otential approximation can b e used to calculate the
daily and then the annual mean values of the three magnetic eld comp onents B B
r
and B the radial meridional and azimuthal comp onents resp ectively The error is
shown to b e no more than Since the neutrino ux propagates radially from the
solar interior to the Earth the absolute values of the two latter comp onents must play a
decisive role in its mo dulation
The high energy b oron neutrino ux E MeV from the solar core has b een
measured at South Dakota USA since The data of several observation runs with
their errors are given in Bahcall As the runs are di erent in length the scale of
data is nonuniform We have applied linear interpolation to obtain a uniform scale as a
series of monthly mean values covering the whole observation interval These have b een
used in turn to yield the annual mean values as well as the mean square ro ot error
The data from individual runs have b een analyzed to give an average signal to noise
ratio equal to This ratio however grows to when the annual mean values
are considered
These facts allow us to compare the neutrino ux variations and the absolute values of
the magnetic eld comp onents along the ux propagation line over a time interval of
years The correlation co e cient b etween the neutrino ux and j B j j B j and
j R j was found to b e and resp ectively Note that correlation
r
co e cient with the Wolf number is as small as On the other hand the correlation
co e cient reaches if only the uniform data series from Stanford is used
The high correlation co e cient indicates a p ossible relationship b etween b oth phenom
ena As should b e exp ected it is most pronounced when direct physical parameters of
magnetic elds are considered Relationship b etween the neutrino ux and the average
eld comp onents B B B is practically absent correlation co e cient
r
from to
Besides South Dakota neutrino measurements though much shorter series were also
obtained with the Japanese neutrino detector Kamiokande II The annual mean values
of the neutrino ux from b oth detectors show a go o d agreement over the time interval of
It should b e noted that neutrino ux variations over this interval are relatively
small compared to the Wolf numbers so that dep endence on the solar cycle may not exist
This inconsistency can b e avoided by using direct physical parameters In fact the heights
of the solar maxima in Wolf numbers in and are practically equal whereas the
amplitude of magnetic eld comp onents in are much lower than in
37
Besides the year cycle the Ar curve displays a signi cant quasi biennial uc
tuation Sakurai Rivin In time variations of the absolute magnetic eld
values this uctuation is absent Therefore it should b e suppressed to obtain adequate
correlation co e cients
Suppression has b een realized by smo othing the original data series over year inter
vals For the smo othed data the correlation co e cients of the neutrino ux with j B j
j B j and j B j increases to make and resp ectively The
r
correlation co e cient with the Wolf number also increases but it still remains
37
lower than correlation b etween Ar and the eld comp onents And nally comparison
of the smo othed neutrino data with a uniform series of magnetic eld data from WSO
yields a correlation co e cient as high as
Our conclusions are as follows
The fact that linear correlation b etween the neutrino ux and the solar magnetic
eld increases signi cantly when absolute values of the magnetic eld comp onents along
the solar center Earth line are considered as well as high correlation co e cients
themselves suggest that solar magnetic elds are resp onsible for variations of the high
energy neutrino ux from the solar interior detected at South Dakota
As the absolute values of the magnetic eld comp onents display mainly an year
variation the neutrino ux is mo dulated by the elds in the convection or maybe even
radiative zones in the Sun These are the elds that determine the basic solar activity
cycle with a p erio d of years
The fact that magnetic eld curves do not display signi cant quasi biennial uctua
tion that is present in the curve of the neutrino ux shows that generation of quasi biennial
uctuations has nothing to do with the elds of the basic solar cycle but is rather due to
the thermal pro cesses in the solar core as suggested by Sakurai
Acknowlegment The authors are grateful to J T Ho eksema and J O Sten o for
observation data that were kindly placed at our disp osal prior to publication The work
was sp onsored by the Russian Foundation for Fundamental Research grant N
V N OBRIDKO
Yu R RIVIN
Institute of Terrestrial Magnetism
Ionosphere and Radio Wave
Propagation
of Russian Academy of Sciences
Troitsk
Moscow Region
Russia
References
Bahcall J N Neutrino Astrophysics M Mir p
Ho eksema J T Report CSSA ASTRO USA
Ho eksema J T Scherrer P H WDCA UAG Report Boulder USA
Rivin Yu R AZh
Sakurai K Nature
Voloshin M B Vysotsky M I Okun L B ZhETF
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
February
HU ISSN
POSSIBLE LOW AMPLITUDE LIGHT VARIATIONS OF DI Her
d
The eccentric eclipsing binary DI Herculis B V and B V P e is
an imp ortant test case of general relativity for stars comp osed of non degenerate mat
ter b ecause it is exp ected to have a large relativistic contribution to its apsidal motion
Rudjk bing Guinan and Maloney DI Her has well determined orbital and
physical prop erties and an accurately measured apsidal motion rate of yr
obs
yr determined from the recent analysis of numerous times of primary and sec
ondary eclipses Guinan et al The most remarkable feature of DI Her is that its
observed apsidal motion rate is signi cantly smaller than that predicted by general relativ
ity and classical e ects The total predicted rate of apsidal motion is yr
g r cl
yr where the general relativistic term is the ma jor contribution
We are currently carrying out an intensive study of DI Her to search for the reason s
for the large discrepancy b etween the observed and predicted apsidal motion rates In a
previous pap er we have re ned the value of the apsidal motion rate and have also searched
for evidence of variations in the O C s of the photo electric eclipse timings obtained over
the last years that could arise from the light time e ects of a p ossible third b o dy
Guinan et al No evidence of the presence of a third b o dy was uncovered from
this analysis
Another p ossible solution for the smaller than exp ected apsidal motion rate is tidal
dissipation of the system s angular momentum arising from induced pulsations in the
stars as they move in their eccentric orbit see Papaloizou and Pringle Savoniji and
Papaloizou In this case the discrepancy in apparent apsidal motion is pro duced
by a decrease in the orbital eccentricity as the orbit circularizes However as discussed by
Guinan and Maloney the rate of change of the eccentricity needed to explain the
observed discrepancy is large e ' yr and the induced pulsations in the stars
if present must b e signi cant and should b e observable With this in mind we carried
out intensive UBV photo electric photometry of DI Her using the Fairborn Villanova m
Automatic Photo electric Telescope APT on Mt Hopkins Arizona
Many eclipse timings have b een obtained for DI Her but there have b een few attempts
to observe the system for a signi cant amount of time outside of eclipses During the
springs of and DI Her was observed continuously with comparison and check
stars for up to hours on several nights outside of eclipses A description of the
equipment lters comparison and check stars and reduction technique is found in Guinan
et al In Figure we present the U and V light curves obtained during
From this gure it is apparent that there are small light variations outside the eclipses
on time scales signi cantly shorter than the day orbital p erio d The variations are
largest in the U bandpass and barely noticeable in the V bandpass In Figure we plot
two long runs on an expanded magnitude and time scale to show examples of the light
variations in the U bandpass To search for p ossible p erio dicities all of the data were
Figure The U and V band light curves of DI Her obtained in are plotted
The magnitudes are di erential measured relative to a nearby comparison star
HD Note the small light variations in the U observations outside the eclipses
Figure The delta U mags of DI Her for the nights of and June are shown
Small systematic variations are noticeable on time scales of several hours
Figure The results of p erio d searches of the U observations outside of eclpises using
the Lomb Scargle metho d are shown The two most prominent p erio ds found are
days and days and are indicated along with several other p ossible p erio ds
analyzed using the Lomb Scargle algorithm Press and Teukolsky
We narrowed down the p ossible range of p erio ds to to days by trial and error
and then analyzed the data in this restricted p erio d range The results are di cult to
interpret b ecause there is no single highly prominent p eak in the p erio dogram This is in
most part caused by the low amplitude nature of the light variations mag
and gaps in the data set Our analysis reveals two prominent p erio ds of day and
day having relative p owers of and on the p erio dogram However there
are other p ossible p erio ds including days with a lower relative p ower of it is
p ossible that the day and day p erio ds are aliases of each other It may
also b e p ossible however to have multiple p erio ds In Figure we plot the U light
curves computed with the day and day p erio ds resp ectively As shown in
the gure b oth p erio ds result in a low amplitude sinusoidal light curve It is di cult
to discern which one of the two p erio ds is b etter The amplitudes of the U B V light
variations are mag mag and mag resp ectively
We are con dent that the light variations discussed ab ove are real However there
is an uncertainty in the source of the variability b ecause all measurements were made
with resp ect to a nearby comparison star HD B V which itself could
b e the source of the observed light variations Although this is unlikely we cannot b e
certain that the comparison is constant in light b ecause the check star HD A
V observations show considerable scatter The scatter in the check star data is
probably due to centering problems with the APT acquiring this faint star the limiting
magnitude for acquisition is mag it is also p ossible that the check star may
b e intrinsically variable We plan further observations next season to resolve this dilemma
using additional comparison stars
The characteristics of the light variations rep orted here whether from DI Her or the
comparison star HD are very similar to those found by Waelkens and Rufener
and Waelkens for a prop osed new class of stars called slowly pulsating
B stars SPB stars These stars generally have sp ectral types ranging from B to B
with luminosity classes of IV V and have light amplitudes of a few thousandths or
hundredths of a magnitude that increase with decreasing wavelength multiple p erio ds
are typically seen in the range of ab out days All the SPB stars seem to show
the same dep endence of the amplitude on wavelength with amplitudes in the U bands
ab out twice as large as in the V bands Furthermore North and Paltani have
found that the ratio of the amplitude in the U B index and V magnitude is very well
correlated with the e ective temp eratures of the SPB stars Waelkens explains
the light variations from the SPB stars as arising from non radial oscillations in the g
mo des with large radial wave numbers k and low orders l The ratio of the amplitude
of the U B to the amplitude in V for our di erential magnitude measures of DI Her
is A A This ratio is similar to that found for SPB stars with sp ectral
U B V
types of B B which is close the sp ectral type of the comp onents of DI Her On the
other hand the comparison star has a sp ectral type of B which is near the observed
upp er limit for SPB stars Furthermore B B SPB stars have an amplitude ratio of
A A which is not consistent with our observed value This evidence
V
U B
lends some supp ort to the hypothesis that the light variations are coming from one or
b oth of DI Her s comp onents and not the comparison star Observations planned for the
future should resolve this issue
If future photometry con rms that the light arise from DI Her rather than the com
parison star these low amplitude non radial pulsations would not b e su cient to explain
the discrepancy in DI Her s apsidal motion rate from tidal dissipation It would app ear
more likely that the light variations may b e quite common for stars of their sp ectral class
and is not related to them b eing members of an eccentric binary system It is p ossible
that many more B type stars will show low amplitude light variations and have not yet
b een discovered b ecause they have not b een adequately sampled
This research was in part supp orted from NSF grants AST and AST
which we gratefully acknowledge
Department of Astronomy
James J MARSHALL
and Astrophysics
Edward F GUINAN
Villanova University
George P McCOOK
Villanova PA
References
Guinan E F Marshall J J Maloney F P I B V S No
Guinan E F and Maloney F P Astrophys J
North P and Paltani S Ast and Astrophys
Papaloizou J and Pringle J E M N R A S
Press W H and Teukolsky S A Comput Phys No
Rudkj bing M Ann Astrophys
Savoniji G J and Papaloizou J C B M N R A S
Waelkens C in Stel lar Pulsations A Memorial to J P Cox A N Cox W M
Sparks and S G Starr eld eds Lecture Notes in Physics Springer p
Waelkens C Ast and Astrophys
Waelkens C and Rufener F Ast and Astrophys
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
February
HU ISSN
ON THE AGE OF FLARE STAR FS AND THE CLUSTER OF PERSEI
As has b een shown earlier there is a correlation b etween the maximum are energy
amplitude which is likely to b e emitted by star of particular magnitude mass and its
age Parsamian This relationship dep ends up on the evolutionary stage of
the are stars and of the clusters in which they have b een observed It follows therefore
that the age of any are star may b e estimated if large are su ciently intense to b e
regarded as maximal is observed
m
During are star searches in the Persei cluster a large are of amplitude U
was observed for the star FS Semkov et al According to these authors the V
V I photometry of FS makes it acceptable for membership in the cluster Flares of
such large amplitudes o ccur very seldom it is therefore likely that the energy emitted in
this particular event is close to the upp er limit describ ed ab ove If star FS is a member
of the Persei cluster we can then estimate the age of the star and of the cluster in
which it resides
According to Semkov et al FS is a faint star of magnitude U and of sp ectral
class M Given a distance of r p c for the Persei cluster the absolute magnitude
of FS is then M U and the absolute magnitude of the are is M According
f
to Table in Parsamian the age of the star would then b e yr and the age
of the cluster at least as large For comparison other indep endent estimates of the age
of this cluster vary from yr to yr Mermilliod Prosser On the
other hand if FS is a eld star then M U Mampaso M and the
f
age would b e yr
Elma S PARSAMIAN
INAOE Mexico
E mail parsam tonali inao ep mx
Byurakan Astrophysical
Observatory Armenia
References
Mampaso A PhD Thesis Univ Laguna Spain
Mermilliod J C Astron Astrophys
Parsamian E S Astro zika
Parsamian E S Astro zika in press
Prosser Ch F Astron J
Semkov E H Tsvetkova K P Tsvetkov M K Prosser Ch F IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
February
HU ISSN
OBSERVATIONS OF A NEWLY DISCOVERED
SU UMa TYPE STAR HV AURIGAE
HV Aurigae was discovered to b e a dwarf nova by Ho meister in Dec He
also found two outbursts on the Palomar charts o ccurred in March and March
on the Palomar charts After the discovery the ob ject has b een little studied except the
additional observations of two outbursts and a nding chart given by Bruch et al
The quiescent identi cation was made by Downes and Shara
Many of the outbursts of HV Aur have probably b een overlooked b ecause of its faint
ness b ecause the maximum visual magnitude in outburst is only ab out However an
outburst was recently noticed by M Iida Variable Star Observers League in Japan on
Nov and announced a brightness variation which was regarded to b e sup erhumps
M Iida in preparation
In order to con rm the sup erhumps and to determine the sup erhump p erio d we made
observations on Nov and using a CCD camera Thomson TH CDA
pixels with m square pixel size attached to the Cassegrain fo cus of m
re ector fo cal length m at Ouda Station Kyoto University Ohtani et al An
interference lter was used which had b een designed to repro duce the Johnson V band
The mo de of on chip summation was employed The observation lasted ab out six
and eight hours on Nov and resp ectively o ccasionally interrupted by clouds The
exp osure time was sec with a read out and saving dead time of sec throughout
observations
We reduced the data using the p ersonal computer based ap erture photometry package
developed by one of the authors T K This package automatically subtracts bias ames
applies at elding and enables us to estimate the instrumental magnitudes The ap erture
00
size was in radius The sky level was determined from pixels whose distance from the
00 00
individual ob jects are b etween to
Figures and show short term light curves of di erential magnitude b etween HV Aur
and a comparison star Table The zero p oint of the ordinate of gures corresp onds to
V The abscissa is Julian Day minus
Table The co ordinates and magnitudes of the comparison and check stars taken from
Guide Star Catalog GSC
R A J Dec J m
V
h m s 0 00
comparison
h m s 0 00
check
h m s 0 00
check
h m s 0 00
check
Figure The short term light curve of HV Aur on Nov
Figure The short term light curve of HV Aur on Nov
Figure Theta diagram by PDM the minimum p oint corresp onds to day
Using three nearby check stars selected from GSC we con rmed the constancy of the
m
comparison star Table within and the r m s error for a single measurement
m
of the di erential magnitude is Although the error is a little bit large b ecause of
clouds the hump like feature is considered to b e real b ecause its amplitude is ab out
mag b eing much larger than the estimated error
By analyzing the light curve using PDM Stellingwerf program within IRAF
package IRAF is distributed by the National Optical Astronomy Observatories U S A
after removing the trend of linear decline we obtained day as the b est
estimate of the p erio d Figure shows the diagram whose abscissa is frequency day
We regarded the feature as sup erhumps b ecause the shap e of the mo dulation rather rapid
rise and following gradual decline is characteristic of a sup erhump of SU UMa stars in
sup eroutburst and only a sup erhump can explain such large amplitude mo dulation in
a dwarf nova in outburst We thus con rmed Iida s identi cation of HV Aur as a new
member of SU UMa type dwarf novae and obtained a sup erhump p erio d of day
The decline rate is mag day which is ab out one fourth of those typically
observed in slow decline phase of usual SU UMa stars More observation is necessary to
reveal the nature of this p eculiarity
The authors are grateful to M Iida for notifying us of the outburst and calling our
attention to this interesting dwarf nova This research has b een partly supp orted by
Research Fellowship of the Japan So ciety for the Promotion of Science for Young Scientists
T K
Daisaku NOGAMI
Taichi KATO
Department of Astronomy
Seiji MASUDA
Faculty of Science Kyoto University
Ryuko HIRATA
Sakyo ku Kyoto Japan
e mail address
nogami kusastro kyoto u ac jp
tkato kusastro kyoto u ac jp
masuda kusastro kyoto u ac jp
References
Bruch A Fischer F J and Wilmsen U Astron Astrophys Suppl
Downes R A and Shara M M Publ Astron Soc Paci c
Ho meister C Astron Nachr
Ohtani H Uesugi A Tomita Y Yoshida M Kosugi G Noumaru J Araya S and
Ohta K Mem Fac of Sci Kyoto Univ Series A of Physics Astrophysics
Geophysics and Chemistry
Stellingwerf R F Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
February
HU ISSN
MORE CLARIFICATION NEEDED FOR NSV
AND VY LYRAE
VY Lyrae and NSV are two stars needing further detailed observations The
slow variability of NSV has not b een con rmed but the star is also a sp ectroscopic
binary with a p erio d of days Batten et al VY Lyrae has b een classi ed as
a W UMa type eclipsing variable by some observers whereas others have rep orted it as
not variable
In the NSV Catalogue Kholop ov NSV is recorded as pg K and is
identi ed with BD and HR The Bright Star Catalogue gives photometric
data V B V K I I I and the Washington Catalogue of Double Stars Worley
00
indicates a v companion at : P A The companion is optical Gri n
and to o faint to a ect estimates of the variability of the primary Variability had
b een discovered by Soloview who rep orted that the star gradually increased in
brightness from May to June Then p o or observing conditions precluded further
observations until August when Soloview and Selivanov found the star to have b egun to
fade The amplitude was rep orted as ab out one magnitude probably only ab out v
Samus Long p erio d variation was susp ected It would b e of interest to ascertain
whether or not there is a correlation b etween the sp ectroscopic and the light variations
The variability of VY Lyr was also discovered in by Soloview and con rmed
by J Kazansky It was rep orted to have varied from to v with W UMa type
h m d
curve in a p erio d of or : Seliwanow Some later observers see Prager
Schneller failed to detect any variation Guthnick and Prager from
observations Zverev and from Since it has b een listed in the GCVS as
cst even though Sandig did rep ort rapid variations among observations b etween
m
and and again among in the fall of amounting to an amplitude of :
but only marginal variation in observations in the fall of
A nder chart repro duced here as the left diagram of Figure as well as a summary
of new observations whose amplitudes do not exceed the observational errors is given
by Zverev and Makarenko The star circled is identi ed as VY Lyrae But that
h m s 0
star is BD at : whereas Prager clearly states
that VY Lyr is not a BD star The p osition given by Prager and in all GCVS catalogues
h m s 0
since : agrees with the p osition given by Seliwanow in his
announcement of the Soloview discovery This star is lab elled as comparison star x
Hence it app ears that x and VY may have b een interchanged on the original chart The
stars marked b c p and x are the comparison stars cited by Zverev and Makarenko for
brightness determinations Step values for c x and p are and resp ectively
while the magnitudes assigned to b and c are and pg It is not clear whether
the published magnitudes corresp ond to star x or BD Moreover it do es not
seem a forgone conclusion that all the observers who found no variation were all examining the same star
Figure Left gure from Russian Variable Stars Supplement
photographic magnitudes Figure at the right from visual BD with relevant BD
numbers indicated The op en circle for VY Lyr is inserted at the p osition of star x in
the left gure For b oth charts North is at the top and East to the left
Table Positions of Critical Stars
Star RA D Mag Remark
h m s 0
NSV : p K
v Optical companion of
v SB d
d d
VY Lyr Period : : or cst
v
? h m
JBAA Period
? m
Probably intended
VY Lyrae is in close proximity to NSV BD The right hand diagram
of Figure is a copy of a p ortion of the BD chart including the area of the variables
Several BD stars in the zone are identi ed The stars marked x b and c in the left
gure are not BD stars while p is BD mag v The approximate p osition
0
of star x is circled in the right gure It is ab out north following BD
h m
An examination of the Carte du Ciel chart for plate center reaching pg
do es show a faint star in the approximate p osition of star x It may well b e VY Lyrae
Indeed Chikinz and Kasitzyne of the Russian So ciety of Amateurs of the Universe s
h m
Knowledge who either con rmed or quoted the p erio d indicated the p osition of
h m s m m
the variable as If for we read then this p osition
do es agree with the lo cation of star x see Table
The p ositions given for VY Lyrae in all the general catalogues of variable stars from
through are consistent with the p osition of star x not the one circled as VY on
the Zverev Makarenko chart Aside from the questioned chart identi cation no reference
to VY Lyr indicates any relation to BD The question remains whether Zverev
and Makarenko merely interchanged the lab els of x and VY Lyr on their chart or do their
observations of non variability corresp ond to BD a star not listed as variable
in either the GCVS or the NSV catalogue
As the amplitudes of b oth NSV and VY Lyrae are small extensive photo electric
observations are needed to ascertain dep endable light curves
Acknowledgements Dr Imants Platais kindly translated passages from the Russian
and contacted N Samus for a Russian publication not available in the Yale Library
Samus sent us translation of the relevant reference to NSV together with his own
comments
Dorrit HOFFLEIT
Department of Astronomy
Yale University
New Haven CT
References
Batten A H Fletcher J M and MacCarthy D G Pub Dominion Astrophysical
Obs
Chikinz A and Kasitzyne W J B A A
Gri n R F Observatory
Guthnick P and Prager R VJS
Kholop ov P N Ed in Chief New Catalogue of Suspected Variable Stars Moscow
Kholop ov P N Ed in Chief General Catalogue of Variable Stars Moscow
Prager R Geschichte und Literatur des Lichtwechsels
Samus N Translation and commentary on Soloview Private communication
to I Platais
Sandig H U A N
Schneller H Geschichte und Literatur des Lichtwechsels
Seliwanow S A N
Soloview A W St Petersburg Pub
Worley C unpublished courtesy of author
Zverev M Russian Variable Stars
Zverev M Russian Variable Stars
Zverev M S and Makarenko E N Russian Variable Stars Suppl pp
and
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
February
HU ISSN
NEW PERIOD DETERMINATION FOR EY Cyg
EY Cyg is a U Gem type dwarf nova The brightness during outburst and minimum are
resp ectively mag and mag Ritter The interval b etween two subsequent
outbursts is ab out days and the duration of the outburst is typically around days
More details ab out the sp ectroscopic observations are given by Smith Sarna Jones
The rst orbital p erio d determination was made by Hacke Andronov
from photographic observations They found
Min JD E
This is the p erio d quoted in the catalogue by Ritter but in our opinion this
determination is very uncertain b ecause of the p o or quality of the data
We obtained CCD photometry in V R I of EY Cyg during two nights in August
and Octob er using the cm Cassegrain telescop e lo cated at the Warsaw Univer
sity Observatory at Ostrowik Exp osure times of and sec were used for di erent
colours and nights We used the standard reduction pro cedure available in Warsaw which
is based on the IRAF reduction package Figure
Figure Figure
The R and I observations are presented in Figures and resp ectively We show only
relative magnitudes in b oth colours b ecause the ma jority of bright stars in our eld of
view are variable We detected a very smo oth light curve mo dulation with an amplitude
of ab out mag The formal error of observations is mag
The p ower sp ectrum p erio dogram is presented in Figure Two p eaks are seen at
1 1
frequencies f day and f day These give orbital p erio ds
1 2
P and P day resp ectively The second p erio d has a
1 2
higher statistical weight further there are evolutionary and sp ectroscopic arguments to
supp ort this value see discussion b elow
From the sp ectra of EY Cyg Smith Sarna Jones we can classify the red
dwarf sp ectral type as dM dM From the calibration by Popper we found that
the mass of the red dwarf comp onent lies in the range M Next from Echevarr a s
mass radius relationship and assuming that the red dwarf main sequence star lls
its Ro che lob e we determined a p ossible range for the orbital p erio d day
From the results of the p erio d analysis only the second value
P day
is consistent with this constraint
Acknowledgements This work was supp orted in part by the Polish National Com
mittee for Scienti c Research under grant and in part by the SERC PATT
under rolling grant GR G
1;3
Marek J SARNA
2
W PYCH
3
Rob ert Connon SMITH
1
N Cop ernicus Astronomical Center Polish Academy of Sciences ul Bartycka
Warsaw Poland
2
Warsaw University Observatory Al Ujazdowskie Warsaw Poland
3
Astronomy Center Division of Physics and Astronomy University of Sussex Falmer
Brighton BN QH UK
References
Echevarr a J Rev Mexicana Astr Af
Hacke G Andronov I L Mitt Ver anderl Sterne
Popper D ARA A
Ritter H A AS
Smith R C Sarna M J Jones D H P MNRAS in preparation
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
HAS THE DELTA SCUTI STAR BE Lyn A COMPANION
The high amplitude Scuti type variation V mag A of BE Lyn HD
HIC was discovered by Oja The p erio d change was discussed in
some pap ers Ro dr guez et al a Liu et al Tang et al Wunder et al
Liu and Jiang Ro dr guez et al Earlier the O C diagram was tted
with a negative parab ola later with a p ositive parab ola The aim of our measurement
was to obtain new p oints on the O C diagram in order to determine the recent p erio d
variation
We carried out photo electric photometry through Johnson UBV lters of BE Lyncis
on three nights Jan and Feb with the cm Cassegrain telescop e and SSP
A photometer of Szeged Observatory Hungary The comparison star was HIC
V mag F The phase diagram of the light curve is plotted in Figure The
p erio d was determined with the Phase Disp ersion Metho d
The new times of maxima are listed in Table where the O C residuals have b een
obtained from the ephemeris
H el J D max E
The O C diagram N can b e seen in Figure Instead of parab ola we tted a
light time e ect curve supp osing a cyclic p erio d variation due to orbital motion in binary
system The parameters of the t and their estimated errors are given in Table
Accepting M M mass for the pulsating comp onent Claret et al
1
Ro dr guezet al b we can calculate the semi ma jor axis of the orbit of the secondary
and its mass with iteration Table The errors are due to the uncertainty of the P and
M The results suggest a red or brown dwarf companion which is probably not detectable
1
in the sp ectrum of BE Lyn due to its low brightness The calculated orbital radial
velocity amplitude K of the delta Scuti star is very small therefore the sp ectroscopic
measurements cannot help to con rm the binary nature
There is an interesting p ossibility to determine the pulsation constant J rgensen and
Gr nbech Combining Kepler s third law and the pulsation constant formula
!
1 2
3
G M a
1
M M and Q P
1 2 pul
2 3
2
P R
1
or b
we obtain
1 2 3 2
R M P
1 2 pul
Q
P a M
or b 1
Figure Phase diagram of BE Lyn P day T
0
Figure O C diagram of BE Lyn with the tted light time curve P day
Table Times of maximum light in early
No Hel JD O C day
Table Parameters of the light time curve
P day
or b
6
a sin i k m
1
e
t O C
0
K k m s
5
f M
2
4
A day
O C
Table Inclination semi ma jor axis of the orbit and mass of the companion
i deg a AU M M
2
Adopting P days P days R R a
pul or b 1
AU M M and M M we calculated Q This
1 2
value corresp onds to the radial fundamental mo de eg Petersen and Jorgensen
Ro dr guez et al b and Garrido et al also concluded that this mo de is
excited
On the other hand accepting M and R Ro dr guezet al b the m e
1 1
and m e mo dels of Milligan and Carson give for the linear adiabatic
p erio ds P days with an average of P days which is very close to
the observed P The pulsation constant from these mo dels Q which
pul
is similar to the value calculated ab ove
This means that the physical parameters of the star the radial pulsation in the funda
mental mo de and the binary orbit determined from the O C diagram are in agreement
We conclude that BE Lyn may have a low mass companion Of course the binary
hypothesis can b e con rmed only a few years later
We used the SIMBAD database op erated at CDS Strasb ourg France This work was
supp orted by Hungarian OTKA Grant No T We would like to express our thanks
to J Vink oand J G alfor discussion
L L KISS
K SZATMARY
Astronomical Observatory and
Dept of Exp erimental Physics
JATE University
Szeged D omt er
H Hungary
Internet L Kiss physx u szeged hu
References
Claret A Ro dr guez E Garc a J M Rev Mexicana Astron Astrof
Garrido R Garc a Lobo E Ro dr guez E Astron Astrophys
J rgensen H E Gr nbech B Astron Astrophys
Liu Y Y Jiang S Y Cao M Inf Bul l Var Stars No
Liu Z Jiang S Y Inf Bul l Var Stars No
Milligan H Carson T R Astrophys Space Sci
Oja T Astron Astrophys Suppl Ser
Oja T Astron Astrophys
Petersen J O J rgensen H E Astron Astrophys
Ro dr guez E L opez de Co ca P Rolland A Garrido R a Rev Mexicana Astron
Astrof
Ro dr guez E Rolland A L opez de Co ca P b Astrophys Space Sci
Ro dr guez E L opez de Co ca P Costa V Mart n S Proc IAU Col l Cape
Town preprint
Tang Q Q Yang D W Jiang S Y Inf Bul l Var Stars No
Wunder E Wieck M Garzarolli M Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
PRECISION B V LIGHT CURVES OF EK COMAE BERENICES
EK Comae Berenices was discovered by Kinman et al in a study of elds
near the north galactic p ole He identi ed it as a W UMa variable The pap er includes
accurate p ositions a nder chart and a list of photographic magnitudes giving a range of
to mag This binary was brought to our attention by AAVSO observer Borovicka
who conducted a thorough visual investigation determining the preliminary light
elements to b e
d
JD Hel Min I : E
making it among the shortest p erio d non degenerate systems known
Our present observations were made on and February and May
at Lowell Observatory Flagsta Arizona A thermo electrically co oled EMI S S
catho de PMT was used in conjunction with the m National Undergraduate Research
Observatory re ector Approximate co ordinates of the variable comparison and the check
star are given in Table and are designated as star d and c resp ectively on the charts
by Kinman et al Ab out observations were taken in each passband
Table
Star R A Dec
h m s
EK Com :
h m s
Comparison :
h m s
Check :
Five mean ep o chs of minimum light were determined from the observations made dur
ing two secondary and three primary eclipses The bisection of chords technique was
utilized in their determination These minima are given in Table accompanied by their
probable errors in parentheses The ve precision ep o chs along with eight times of low
light from Kinman et al the ep o ch by Borovicka and the visual timing by
Lo cher were introduced into a weighted least squares solution to obtain a linear
ephemeris A quadratic ephemeris was also determined In b oth of these calculations
visual timings and photographic timings given a weight of While photo electric obser
vations were given a weight of with the exception of our last timing which was given
a lower weight of The improved ephemerides are
d
JD Hel Min I : E and
JD Hel Min I E E
Figure Photo electric light curves of EK Com as de ned by the individual
observations
Figure Period b ehavior of EK Com as calculated from Equation
Table
JD HEL
Minimum Cycles O C O C
II
I
I
II
I
Equation was used to calculate the O C residuals in Table and the phases of
the present observations Equation was used to calculate the O C residuals The
quadratic term in the second ephemeris is marginally signi cant and negative Because
of its small magnitude and doubtful signi cance we cannot regard this as pro of that the
present p erio d b ehavior of EK Com is dominated by magnetic breaking More timings of
minimum light are needed b oth from photographic archives and future observations
The B V light curves of EK Com as de ned by their individual observations are shown
in Figure as di erential magnitude variable comparison versus phase The p erio d
b ehavior of the system as calculated from the linear ephemeris equation is shown as
Figure Our preliminary unsp otted solution yields a mass ratio of and a ll out of
for this W type W UMa system The analysis of the observations is underway
?
Ronald G SAMEC
?
Brian CARRIGAN and
?
Eric E PADGEN
Millikin University
Decatur IL USA
?
Visiting Astronomer Lowell Observatory Flagsta Arizona USA
References
Borovicka J J AAVSO
Kinman T D Wirtanen C A and Janes K A ApJSS
Lo cher K BBSAG No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
PERIOD CORRECTION FOR THE NEW ECLIPSING BINARY DHK
Recently Kaiser announced that the th magnitude G star HD
SAO is a detached eclipsing binary which he designated DHK in his discov
ery list He rep orted a preliminary p erio d of days However JG and BH so on
observed the non o ccurrence of an eclipse predicted by this p erio d
Continued visual monitoring by MEB and CS revealed that this eclipsing binary has
an eccentric orbit with secondary minimum o ccurring at phase The rep orted p erio d
days is actually the interval from secondary minimum to the following primary
minimum in a true p erio d of days
Table contains helio centric times of minima obtained to date DHK DT JG and
BH have observed photo electrically MEB and CS have monitored the star visually The
photo electric timings were reduced with a program based on the Kwee Van Woerden
metho d and the mean errors are given These errors are large for photo electric
data due mostly to p o or observing conditions
The p erio d was determined by least squares using the minima from Table The data
were weighted as follows discovery photograph visual and photo electric The
O C residuals in the table were calculated according to the following light elements
d
Min I HJD : E
Figure
Table
HJD Min O C Observer
?
I ptg Kaiser
II vis Baldwin
II vis Baldwin
I p ep Terrell
II p ep Kaiser
I p ep Kaiser
?
Discovery photograph
Figure has DHK s V data and DT s delta V data merged into one graph to show
phase coverage The two eclipses are nearly equal in depth ab out V At this time
our choice of primary eclipse is nominal the slightly greater apparent depth of Min I
b eing similar to the scatter in the observations
In a p oster pap er presented at the January meeting of the American Astronomical
So ciety Terrell and Kaiser DT and DHK estimated the orbital eccentricity to b e
near and noted that the star may b e a distant member of the Hyades cluster Photo
electric and radial velocity observations of this interesting binary system are continuing
and a full analysis will b e published when these observations have b een completed
Dirk TERRELL
Daniel H KAISER
Department of Physics
Washington Street
Astronomy
Columbus IN U S A
University of Calgary
Marvin E BALDWIN
Calgary Alb erta T N N
N Co Rd E
Canada
Butlerville IN U S A
Chris STEPHAN
Jerry GUNN
Andretti Avenue
Skyview Drive
Sebring FL U S A
East Peoria IL U S A
Brian HAKES
N Fox Point Drive
Peoria IL U S A
References
Kaiser D H IBVS No
Kwee K K and Van Woerden H BAN No
Terrell D and Kaiser D H BAAS No abstract
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
FAINT COMPANIONS TO UX ANTLIAE
Recently UBV photometry was provided for stars in the elds of the R CrB type
stars UX Ant and UW Cen Milone later identi cations in several catalogues
Guide Star Catalogue GSC Henry Drap er Catalogue Cordoba Durchmusterung
and Cap e Photographic Durchmusterung of the photometrically observed stars were also
published in these Bulletins Ski Precisely it was said Milone et al Note
Milone Note that the variable star UX Ant has a faint near by companion
but unfortunately there is an erroneous identi cation of the close companion in Note
In fact the reason for the large discrepancy in the B magnitude of the near by star
as indicated in Notes and is that we are referring to di erent stars see Figure
it was star for which we measured B Note whereas for star it was found
V B V Note This is the p oint we want to emphasize here as faint
stars of known brightness neighboring a variable star can b e useful in several resp ects
It is worth mentioning that there are several examples of close companions among the
variable stars of the R CrB type The following cases were noted indicated distances in
arc seconds from the variable are only approximate UX Ant comp onent
B to the NW comp onent B to the NE
UW Cen B to the NNW
Y Mus B to the W
RZ Nor B to the NE
RY Sgr B Andrews et al Feast
Very probably these are not physical pairs but the p oint rather is that the variable
b eing studied can b e misidenti ed when it weakens
L A MILONE
Observatorio Astron omico
Universidad Nacional de C ordoba
C ordoba Argentina
References
Andrews P J Catchpole R M Feast M W Jones D H P Lloyd Evans T and
Walker E N IBVS No
Feast M W Non p erio dic phenomena in variable stars IAU Collo quium Bu
dap est p
Milone L A IBVS No
Milone L A Minniti E R and Paolantonio S IBVS No
Ski B A IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
A LONG PERIOD EARLY F TYPE VARIABLE HR
In summer the early F type variable star HR HD was observed
on nights with the m re ector at Observatorio de Sierra Nevada by means of a
Str omgren Crawford six channel simultaneous photometer
The purp ose of the campaign was to investigate its p ossible SX Phe nature prop osed by
Shuster and Nissen who noticed its slightly low metallicity and a high disp ersion in
V and c light curves They prop osed a variability on unknown time scale and amplitude
m m
ranging b etween and in b oth colours
During the observations HD HD and HD were used as
comparison stars In this campaign di erential measurements were collected with
resp ect to HD in uv by colors unfortunately with large gaps b etween di erent
observing nights The di erential time series b etween HD and HD provided
m m m m
evidence of constancy within u v b V assumed
as mean external errors Similarly the di erential time series b etween HD and the
m m m m
third comparison star HD provided and in the four
colours resp ectively A comparison of the ab ove results with the disp ersions computed for
m m m m
HR versus HD i e u v b V con rms
what rep orted by Shuster and Nissen
Furthermore during each night we found variations in the colour indices b y c and
in the same sense and approximately phased with the V light curve This can b e seen
in Figure where the observed light and colour index curves are shown for the night of
September as an example Variations in the m color index can b e forecasted but
due to its intrinsically low amplitude in the scanty data of this campaign they cannot b e
revealed
In spite of the large gaps in the data set sp ectral analysis p erformed on these p oints
by means of Vanicek s least squares technique provided evidence of a principal
d
frequency of d p erio d and the absolute absence of signals in the
d region where Sct and SX Phe pulsational frequencies are generally found However
such a p erio dicity fails to explain the whole signal contained in the time series further
frequencies must b e present even if their determination is b eyond the p ossibility of such
a small amount of measurements
In a pulsational scenario the p erio d found should b e related to a non radial g mo de
pulsation never rep orted in the lower part of the instability strip at the time when the
observations were collected Nevertheless in the last decade a number of ob jects in this
region of the HR diagram showing variability on longer time scales with resp ect to typi
m
cal Sct or SX Phe pulsations and with amplitudes b elow were rep orted by various
authors and gathered into a group of ab out ten ob jects b elieved to undergo the same
phenomenon Mantegazza et al The physical nature of their b ehaviour its still
Di erential light and colour index curves of HR with resp ect to HD versus
Helio centric Julian Day in the night September
Figure Position of the new variables in HR diagram Main Sequence track is taken
from Philip and Egret while hot and co ol b order of the instability strip from
Ro dr guez et al
Table Comparison b etween HR and other stars in the group of new early F type
variables Data are taken from the corresp onding references quoted in the text HR
Str omgren scolours are taken from Shuster and Nissen while its radial velocity
from Uesugi and Fukuda means photometric frequency
ph
b y m c v sin i Name
ph
HD
HD
HD
Dor
Aur
HR
a matter of discussion and b eside non radial g mo de pulsation also mo dels taking into
account sp ots and binarity have b een prop osed and developed Some of the stars in the
sample have b een studied more thoroughly HD Abt et al HD
and HD Mantegazza et al Aur Krisciunas et al Dor Balona
et al The principal characteristics of these stars to b e compared with HR
results are brie y summarized in Table
In order to lo cate HR in the Hertzsprung Russell diagram we computed its abso
lute visual magnitude by means of Philip and Egret calibrations obtaining a value
M As can b e seen in Figure our star lies in the same region where all of the new
V
variables were found Similar p osition in HR diagram and similar photometric b ehaviour
make HR a p ossible candidate b elonging to this type of variables
A number of to ols are at present b eing studied Zerbi and Garrido in order to
achieve a b etter understanding of the b ehaviour of the whole sample and to select the
most suitable b etween the prop osed mo dels Such to ols are based on comparison b etween
colour and radial velocity curves that should present a di erent b ehaviour in the case of
sp ots binarity or pulsation In addition frequencies close to an integer multiple of d
as that found in HR as well as in many other variables in the sample suggest to
avoid night day cycle through a multisite campaign
Any further observations should therefore b e planned within a co ordinated multisite
campaign devoted to multicolor photometric observations and p ossibly with asso ciated
high resolution sp ectroscopy
E RODRIGUEZ
F M ZERBI
Instituto de Astrof sicade Andalucia Apto E Granada Espa na
Dipartimento di Fisica Nucleare e Teorica Universit adi Pavia Via Bassi I Pavia Italia
References
Abt H A Bollinger G Burke E W ApJ
Balona L A Hearnshaw J B Ko en C et al MNRAS
Krisciunas K Aspin C Geballe et al MNRAS
Mantegazza L Poretti E Antonello E Zerbi F M APS Conf Series
Mantegazza L Poretti E Zerbi F M MNRAS
Philip A G Egret D A AS
Ro driguez E L opez de Co ca P Rolland A Garrido R Costa V A AS
Shuster W J Nissen P E IBVS
Uesugi A Fukuda I Revised Catalogue of Stel lar Rotational Velocities Kyoto
University Japan
Vanicek P ApSS
Zerbi F M Garrido F M in preparation
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
ONSET OF PULSATION OF V IN M
The variable V in the globular cluster M was discovered by Mannino on plates
obtained in the years in Asiago Observatory From ab out plates a p erio d
of day has b een determined and light curve constructed It is interesting to note
that this newly discovered RRc variable had b een chosen as comparison star by Bailey in
his previous study Bailey
Notni and Oleak measured the brightness of this star on plates taken by Guth
nick and Prager previously to Mannino s observations in the years and in
Potsdam Babelsb erg Observatory On these plates light variation could not b e detected
Brightness measurements were carried out on the plate material of the Konkoly Obser
vatory The light curves folded on Mannino s p erio d including the Bab elsb erg
material show clear light variation only in the years and
As the plates were originally obtained to study p erio d changes the temp oral distribu
tion of the data is inconvenient and a high level of noise inherent in the photographic
metho d is present Still existence of any de nite p erio dic variation can b e determined
A larger amount of plates were obtained in the years and Fourier
analysis of the data for these years was p erformed
In the Figures the light curves of the years Mannino s data and
can b e seen folded on Mannino s p erio d and the amplitude sp ectra with their sp ectral
windows from the years Mannino and
The Fourier analysis of the data of and do es not show any frequency but
noise We reanalysed Mannino s observations and we could con rm that the p erio d
of the star in and given by Mannino was correct
In a p erio d of day and magn amplitude was found The p erio d di ers
from the one given by Mannino by ab out day This would b e far b eyond the rate of
p erio d change typical for RRc stars So it can b e concluded that the deviating p erio d and
the small amplitude of the light curve might show the presence of a non radial pulsational
comp onent In the year the sp ectrum shows noise with increased amplitude which
would indicate scatter of the data exceeding observational error
The light curve of magn amplitude from and de ned by Mannino is
that of a typical RRc variable of radial mo de pulsation The same holds for the Budap est
material from the years and From the seventies the limited number of the
data shows only scatter slightly exceeding the photographic error At any rate it suggests
diminishing amplitude of any of the p erio ds M15 V99 1937-1954-1956-1963 15.4 15.6 15.8 16
magnitude 16.2 16.4 0 .5 1 1.5
15.4 15.6 15.8 16
magnitude 16.2 16.4 0 .5 1 1.5
15.4 15.6 15.8 16
magnitude 16.2 16.4 0 .5 1 1.5
15.4 15.6 15.8 16
magnitude 16.2 16.4 0 .5 1 1.5
phase
Figure Light curves from Budap est observations in the years and
folded on Mannino s p erio d The light curve from is based on Mannino s observations
.2 1.2
1938 1 .15 .8 .1 .6 .4 amplitude .05 .2 0 0 0 1 2 3 4 5 -2 -1 0 1 2 .2 1.2
1951 1 .15 .8 .1 .6 .4 amplitude .05 .2 0 0 0 1 2 3 4 5 -2 -1 0 1 2 .2 1.2
1954 1 .15 .8 .1 .6 .4 amplitude .05 .2 0 0 0 1 2 3 4 5 -2 -1 0 1 2 .2 1.2
1990-91 1 .15 .8 .1 .6 .4 amplitude .05 .2 0 0 0 1 2 3 4 5 -2 -1 0 1 2
frequency frequency
Figure Amplitude sp ectra with their sp ectral windows from the years
from Mannino s data and
In the years and the structure of the sp ectra in spite of the very low amplitude
might indicate some oscillation inside the star
Time and more accurate photometry can only solve the problem of this unique cluster
member It is suggested that the starting of pulsation has b een caught
This study was partly supp orted by Hungarian OTKA grant I
K BARLAI and
B SZEIDL
Konkoly Observatory Budap est
Hungary
References
Bailey S I Harv Ann Part
Mannino G Memorie Soc Astr Ital
Notni P Oleak H Astron Nachr
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
NEW MINIMA TIMES AND PERIOD BEHAVIOUR FOR THE ECLIPSING
VARIABLES RT ANDROMEDAE i BOOTIS AND GO CYGNI
In the present rep ort new photo electric minima times of RT And i Bo o and GO
Cyg are given as they were derived from our observations made either in Greece or in
Romania
The photo electric observations of RT And and i Bo o were made during and
resp ectively with the two beam multi mode nebular stellar photometer of the Na
tional Observatory of Athens attached to the inch Cassegrain re ector at the Kryone
rion Astronomical Station While those of GO Cyg were made during with an EMI
B type photo cell attached to the cm Cassegrain telescop e of the Bucharest Ob
servatory The lters used in b oth cases are in close accordance with the standard UBV
and the reduction of the observations has b een made in the usual way Hardie
RT Andromedae
The short p erio d variable RT And BD A HD is a very interesting
eclipsing binary with many p eculiarities in its light curve It is classi ed as an RS CVn
type system with b oth comp onents to b e main sequence stars in contrast to the main
group which contains active sub giant stars Budding and Zeilik
From our observations made during new minima times were derived and given
in Table I The O C diagram of the system based on all minima times found in the
literature p oints is presented in Figure a quadratic least squares tting applied
to all of them improves Williamon s ephemeris formula to
d d
Min I : E : E
showing that its orbital p erio d is decreasing
A detailed analysis of the p erio d variations of RT And has b een recently made Rovithis
Livaniou et al Moreover our new minima times together with the last photo
electric ones yield the following linear ephemeris
d
Min I : E
which is prop osed for the future observations of RT Andromedae
Table I Photo electric Minima Times of RT And
Hel JD O C O C O C
I II III
days days days
Figure The O C diagram of RT And based on photographic squares and
photo electric diamonds minima times The C values have b een calculated using
Williamon s linear ephemeris
In Table I the residuals O C O C and O C have b een calculated according
I II III
to Williamon s ephemeris formula
d
Min I : E
Kholop ov s
d
Min I : E
and our new one given by equation resp ectively They are the mean values of our
B and V observations and have b een computed using Kwee Van Woerden s
metho d
i Bo otis
The eclipsing binary i Bo o is the fainter companion B C of the close visual binary
ADS It is one of the mostly observed systems since its light curves exhibit active
and quiet p erio ds and its p erio d is variable e g Bergeat et al Rovithis et al
Oprescu et al Gherega et al
From our recent photo electric observations of i Bo o two new minima times have
b een found and given in Table I I
Table I I Photo electric Minima Times of i Bo o
Hel JD Min Fil O C O C O C
I II III
days days days
I V
I B
II V
II B
In Table I I the residuals O C O C and O C have b een calculated using
I II III
Kwee Van Woerden s metho d and according to the following ephemeris formulae
d
Min I : E Duerb eck
d
Min I : E
Rovithis et al
d
and Min I : E
Oprescu et al
They t pretty well the last O C diagram for i Bo otis Gherega et al based
on Oprescu s et al ephemeris formula showing that the p erio d of the system
continues to increase
GO Cygni
The eclipsing binary GO Cyg BD has b een observed photo electrically many
times after its discovery and many minima times can b een found in the literature from
which its p erio d was found to b e variable e g Purgathofer and Pro chazka Sezer
et al Hall and Louth
From our recent observations of GO Cyg three new minima times were derived and are
presented in Table I I I
Table I I I Photo electric Minima Times of GO Cyg
Hel JD Min Fil O C O C O C
I II III
days days days
II B
II V
II V
In Table III the residuals O C O C and O C have b een calculated using
I II III
Kwee Van Woerden s metho d and according to formulae
d
Min I : E
Kholop ov
d
Min I : E
Sezer et al
and
d
Min I : E
SAC
The newly observed minima times are in accordance with the O C diagram of GO
Cyg Sezer et al showing that the p erio d of the system continues increasing A
detailed analysis of the p erio d variations of GO Cyg based on the new metho d developed
by Kalimeris et al will b e done later
Acknowledgement This work was partly supp orted by NATO grant No
H ROVITHIS LIVANIOU G OPRESCU
P ROVITHIS A DUMITRESCU
Section of Astrophysics Astronomical Institute
Astronomy Mechanics Academia Romana
Dept of Physics Street Cutitul d Argint
Athens University Bucharest
Zografos Romania Greece
References
Bergeat J Lunel M Sibile F Van t Veer F A A
Budding E Zeilik M ApJ
Duerb eck H W IBVS No
Gherega O Farkas L and Horvath A IBVS No
Hall D and Louth H J A A
Hardie R H in W A Hiltner Ed Stars and Stellar Systems Vol I I Astronomical
Techniques The University of Chicago Press Chicago
Kalimeris A Rovithis Livaniou H Rovithis P A A
Kholop ov P N General Catalo que of Variable Stars Moscow
Kwee K K Van Woerden H Bul l A I Neth
Oprescu G Suran M D Popescu N IBVS No
Oprescu G Suran M D Popescu N IBVS No
Purgathofer A Pro chazka F Mitt Un Stern Wien
Rovithis P Rovithis Livaniou H A ASS
Rovithis Livaniou H Rovithis P Kalimeris A Oprescu G Dumitrescu A Suran
M D Rom Astron J in press
SAC Ro cznik Astronomiczny Observatorium Krakowskiego No
Sezer C G ulmenO G ud ur N IBVS No
Williamon R M PASP
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
OPTICAL MONITORING OF TWO X RAY TRANSIENT SOURCES
The X ray transient pulsar GRO
The hard x ray transient pulsar was detected in at the p osition RA
h m s 0 00
: and : Stollb erg et al Tanaka
To analyse its long time b ehaviour and or p ossible low energy emission we have inves
tigated the p osition of GRO on archival patrol plates from the collections of the
Sonneb erg and Bamberg Observatories Altogether Sonneb erg patrol plates reaching
the limiting magnitudes of and taken in the years as well as Bamberg
patrol plates reaching limiting magnitudes and taken during the time interval
i e total of plates representing hrs of exp osure have b een analysed No
optical activity has b een detected from the p osition of the X ray pulsar with the ab ove
mentioned threshold
We conclude that the optical emission of the transient pulsar is either an infrequent
phenomenon and or do es not reach the limiting magnitudes on corresp onding plates
The X ray Nova GRS GROJ
The X ray nova in Ophiuchus was detected in Ballet et al with a radio
and optical counterpart exhibiting brightening from to mag Mirab el et al
The p osition of the radio and optical counterpart has b een measured as follows
h m s 0 00
Mirab el et al RA : :
We have analysed this p osition on archival plates from the collections of the Leiden
Sonneb erg and Bamberg Observatories in order to see whether or not this is a rep eating
phenomenon We have analysed archival patrol plates from the Sonneb erg collection
reaching typical limiting magnitudes of to taken during the time p erio d from
to Franklin Adams archival plates from the Leiden Observatory collection
with typical limiting magnitudes taken during the time p erio d and
archival plates taken at the southern stations of the Bamberg Observatory with typical
limiting magnitudes of to taken in the years to i e total of plates
representing hrs of exp osure We have not found any sign of optical activity from
this p osition exceeding the corresp onding magnitude limit We conclude that either the
ob ject was optically inactive in the time intervals covered by the plates or that the p ossible
brightenings were b elow the plate threshold
Acknowledgements We acknowledge the supp ort by the Sonneb erg Leiden and Bam
b erg Observatories in providing their archival plates and also the supp ort by the grant
No of the Academy of Sciences of the Czech Republic
R HUDEC
Astronomical Institute
Academy of Sciences of
the Czech Rep
CZ Ond rejov
Czech Republic
References
Ballet J Denis M Gilfanov M and Sunyaev R IAUC No
Mirab el I F Ro driguez L F and Cordier B IAUC No
Stollb erg M T Finger M H Wilson R B Harmon B A Rubin B C Zhang N
S and Fishman G J IAUC No
Tanaka Y IAUC No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
1
OBSERVATION OF A V R TRANSITION IN THE Be STAR Oph
As part of our long term high resolution sp ectroscopic monitoring programme of Be
stars we have rep eatedly observed the interesting equatorial Be star Oph HR
B IV Ve v sin i km s During the past two decades its H emission strength
has b een observed to steadily increase from F F in Gray Marlb orough
c
to F in see Table This latter value corresp onds to equivalent width
c
W A thus presently making Oph one of the brightest Be stars at H
We have mainly investigated the H and the Fe i i emission lines Our data cover
the ep o ch and have b een measured at ESO m Coud e Auxiliary Telescope
observers Hanuschik Hummel at the m telescop e at the German Spanish Obser
vatory DSAZ on Calar Alto Spain observers Hummel Vrancken and at the m
Ond rejov telescop e observer Ste Resolution R has b een around ex
cept for the Ond rejov data The signal to noise ratio is usually several hundred
except for some of the Fe i i pro les shown here Pro le parameters are collected in Table
Our pro le survey in Fig demonstrates that in April and since June
again Oph has shown asymmetric single or double p eak pro les at H and extremely
asymmetric so called steeple pro les in Fe i i Esp ecially striking is the inversion of
asymmetry from V R in to R V back to V R
The steeple type Fe i i pro le shap e and the cyclic V R asymmetry are two connected
phenomena b oth b eing pro duced by a large scale density inhomogeneity This structure is
likely to b e a global density wave slowly precessing under the in uence of the centrifugally
attened B star Hanuschik et al
In Oph showed a sudden onset of cyclic V R variability after at least years
of symmetric double p eak structure V R Its present full V R cycle time is only
years rather short if compared to other such Be stars which have typical cycle duration
of ab out years With this cycle time the rst V R transition must have o ccurred
in early but escap ed detection In we have b een fortunate enough to observe
the second V R transition b oth in H and Fe i i see Fig This transition o ccurred
in November and app ears to have lasted only a few months as a comparison of
our data from September H R V November R V and June
V R clearly shows
The transition app ears quite smo oth with a gradual decrease in asymmetry in
from April over September to November and a new increase with opp osite sign to
August The overall time of observed V R shap e is only a few months a small fraction
of the full cycle time Such temp oral b ehaviour agrees well with the exp ectation that the
slop e of the V R evolution is sinusoidal with much longer p erio ds of V R asymmetry
than with V R
1
Based on observations obtained at the Europ ean Southern Observatory La Silla Chile at the German Spanish Obser vatory DSAZ Calar Alto Spain and at the Ond rejov Observatory Czech Rep
Figure H and Fe i i emission line pro les in Oph left b oth on a common
helio centric velocity scale The ux scale of the Fe i i lines is expanded by a factor of
Figure Comparison of the and pro les of Oph demonstrating the
V R ! V R transition in November
Table Line parameters for H and Fe i i
a
Date H Fe i i
b c
W A V R F F W mA V R F F
p p c
c
d
e
a
Octob er
b
V R F V F F R F
c c
c
average intensity if two p eaks exist
d
averaged from measurements on June and
e
averaged from measurements
An interesting observation is that shortly b efore the V R transition H and Fe i i
pro les showed slightly opp osite V R b ehaviour in September V R in H V R
in Fe i i This may b e partly due to the fact that in a certain critical parameter range
the sup erp osition of di erent line broadening mechanisms causing the wineb ottle type
in ections and the pro le p eaks causes slightly inverse V R ratios in H and the Fe i i line
Alternatively this may b e indicative of a certain time lag b etween the V R transition
in b oth lines due to very di erent optical depth and therefore di erent contributing disk
regions Thus these measurements contain valuable information for the mo delling of the
density wave
A very pronounced decrease in equivalent width o ccurred in November by
after the star had shown a stable value of A for almost half a year b efore Half a year
later W was again observed at higher values remaining constant thereafter for at least
two months Such rather strong variability seems to b e uncommon in this star However
we are not fully sure that the sudden decrease is not a mere chance coincidence If it is
physically related to the V R transition then this observation may b e interpreted as
result of the relatively small velocity gradient averaged across the whole emitting disk
at the moment of symmetry V R as compared to the situation shortly b efore and
after the transition when the velocity gradient b ecomes larger again
We strongly encourage other observers to continue to monitor this interesting Be star
at high sp ectral resolution in order to follow up its V R b ehaviour and to furthermore
do cument its emission strength variability pattern
R W HANUSCHIK
S STEFL
W HUMMEL
M VRANCKEN
Astronomisches Institut Ruhr Universit at Postfach D Bo chum
Germany
Astronomical Institute Czech Acad of Sciences CZ Ond rejov Czech Republic
Astrofysisch Instituut Vrije Universiteit Brussel Pleinlaan B Brussel
Belgium
References
Gray D F Marlb orough J M ApJS
Hanuschik R W Hummel W Dietle O Sutorius E A A in press
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
PHOTOMETRIC EXAMINATION OF CP PECULIARITY FOR
HD HR HR and HR
In the course of a programme aimed at checking sp ectroscopic p eculiarity assignments
of chemically p eculiar stars on the upp er main sequence b elonging to group CP in older
2
terms the CVn variables we have chosen the ab ove stars for runs at the L Figl
Observatory Univ of Vienna on the summit of Sch op using its cm photometric tele
scop e equipp ed with a classical one channel photo electric photometer photomultiplier
EMI A Peltier cooled Observer was AS
The lter system employed is that of a Maitzen which has b een shown to
identify CP stars as e ectively as classi cation sp ectroscopy Maitzen and Vogt
Details on the lters g and g were given in Maitzen and Flo quet the third lter
is a conventional Str oemgrensystem lter y
Measurements for this programme were obtained on August August and
Octob er stars were chosen to de ne the normality line of the index
a g g y versus the colour index b y the deviation of which has b een de ned
as a value A measurement series for a programme star consisted of rep eats of the
sequence g g y each covering seconds of integration The resulting mean error for
the HR stars was millimags in a and millimags in g y Only for the relatively
faint HD the error was millimags in a and millimags in g y
We have taken the b y values from Hauck and Mermilliod but no such value
seems to have b een published for the p eculiarity candidate HD Since a very go o d
correlation b etween b y and the colour di erence g y had b een found on previous
o ccasions we made use of it also in the present case Fig shows this correlation with a
slop e of
Figure Correlation b etween g y and b y b oth in mmags Candidates for
p eculiarity are represented by op en circles
Figure Peculiarity index a vs b y b oth in mmags Op en circles are for
measurements of CP candidates Full line is the lo cus of normal stars
From this correlation a value b y can b e inferred for HD Even
considering an error of mag of this value this will only very marginally in uence
the resulting a value The relationship a vs b y is displayed in Fig A regression
curve yields
2
a b y b y
with a scatter of only millimags for the normal stars Table gives the results of our
a system measurements individually for the nights expressed in millimags
RESULTS AND DISCUSSION
HD Renson Catalogue RE
North has shown that this binary has the shortest orbital p erio d days
known among those which host a CP star Although he rep orts a V G
indicating a CP star photometrically North private communication asked for an in
dep endent con rmation of this result Without any doubt we can give this con rmation
based on our photometry
our a values millimags obtained on JD resp
classify the p ertaining comp onent as medium strong p eculiar star with a slight indication
that it may b e variable Variability should not b e very pronounced according to the
orbital analysis of North since the star seems to b e seen nearly p ole on Future
observations may help to get more insight into this very sp ecial example of a binary
containing a CP star whose characteristics are obviously preserved despite the imp ortant
tidal forces exerted by the nearby companion North
HR RE
Cowley et al have classi ed this star A V Si This prompted Flo quet
to reobserve this ob ject and she derived A I I I for this star Our a result obtained on
JD is in agreement with a non p eculiar star
HR RE
Osawa classi ed this star B Vp with the remark that the K line is as strong
as in A and that He I is visible Flo quet however classi es this ob ject as
normal A V star which is in agreement with our completely normal a values obtained
on JD and
Table a photometry
Ob ject b y a a g y
HD
HR
HR
HR
HR
HR
HR
HR
HR
HR
HR
HR
HR
HR
HR HD
Contrary to the preceding three stars this ob ject is not contained in the Renson cata
logue of Ap and Am stars It has b een included in our programme b ecause a photometry
of Vogt et al exhibited a marginally p eculiar value mags
Except for the observation of Hauck that HR is one of stars classi ed
as dwarfs in the Bright Star Catalogue but which have the same Geneva colours as
giants this star do es not show a p eculiar b ehaviour and lacks CP characteristics Our
photometric value has b een obtained on JD
As a summary we arrive at the conclusion that only HD is photometrically a
CP star Because of its sp ecial nature as member of a close binary system it deserves
further observations The other three stars are normal in our photometry
This research has made use of the Simbad database op erated at CDS Strasb ourg
France
A SCHNELL
H M MAITZEN
Institut f ur Astronomie
Universit atWien
T urkenschanzstr A Wien
maitzen astro ast univie ac at
References
Cowley A P Cowley C R Jaschek M Jaschek C AJ
Flo quet M A AS
Flo quet M A AS
Hauck B A A
Hauck B Mermilliod J C A AS
Maitzen H M A A
Maitzen H M Flo quet M A A
Maitzen H M Vogt N A A
North P in The th Workshop and Meeting of Europ ean Working Group on
CP Stars eds I Jankovics I J Vincze ELTE Gothard Astrophysical Observatory
Szombathely p
Osawa K ApJ
Renson P Catalogue G en eral des Etoiles Ap et Am Institut d Astrophysique
Universit ede Li ege
Vogt N Kerschbaum F Maitzen H M A A submitted
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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March
HU ISSN
PHOTOMETRIC VARIABILITY OF THE ELLIPSOIDAL STAR
AND SPECTROSCOPIC BINARY CAMELOPARDALIS
For several years we have used Cam BS HD ADS Sp A V
but see b elow V as our principal check star for di erential photometry of
Aurigae with BS Sp A V V as the comparison star Recently over
the course of a seven night photometric run at Mauna Kea we noticed that the nightly
means of Cam vs BS were the same only every other night So we added a second
check star BS Sp F V V to the observing sequence Photometry of
the second check star with resp ect to BS showed it to b e constant to within the
observational errors A p ower sp ectrum of the recent Cam vs BS data indicated
a p erio d just under two days but we susp ected that it was just an alias of data taken
primarily at a single site However a fo otnote in the Bright Star Catalogue indicated that
Cam is a known sp ectroscopic binary with a p erio d of days It o ccurred to us that
Cam could b e an ellipsoidal variable star with a photometric p erio d equal to half the
orbital p erio d
A simbad search p ointed us to a pap er in which Lucy and Sweeney recom
puted under the assumption that the orbit is exactly circular the orbit determined by
Harp er on the basis of Ottawa and Lick radial velocities It is not clear from their
pap er whether Lucy and Sweeney to ok into account the additional velocities measured at
the Dominion Astrophysical Observatory and used by Harp er to re ne the orbital
p erio d The exact p erio d and its uncertainty which Lucy and Sweeney did not give
are of particular interest to us as they enable us to extrap olate to the present day the
sp ectroscopic phase of the system for comparison with the photometric phase We there
fore recomputed the orbit ourselves from the Lick Ottawa and Dominion Astrophysical
Observatory radial velocities We know of no others of comparable precision An empir
ical adjustment was made to the zero p oint of the Lick data and the three sources were
weighted so as to equalize the variances of their residuals The solution is
P days
T JD
0
1
V km sec velocity
0
1
K km sec
e
9
a sin i m
1
f m M
Here T is the ep o ch of maximum velocity when the comp onent we see is receding
0
from us a sin i is the true radius of the orbit of the primary ab out the center of mass
1
pro jected in the line of sight f m is the mass function
Figure Di erential photometry of Cam BS vs BS The three p oints
with error bars are nightly means of data by Luedeke The rest are individual
di erential magnitudes obtained at Mauna Kea
Figure Power Sp ectrum of data obtained by Guinan and McCo ok in The
frequency f and its one day alias are indicated
In Figure we give the data recently obtained also showing the least squares sinusoid
t to the data obtained at Mauna Kea with a p erio d equal to half of the sp ectroscopic
p erio d The derived photometric amplitude is mmag If we adopt an ep o ch of
HJD the derived phase of minimum light is where the negative
phase means that the photometric minimum o ccurs slightly after the given ep o ch The
go o dness of t is mmag for a single observation
Do previous data con rm the variability The b est set to use was obtained over a
day p erio d in by Guinan and McCo ok with the Pho enix APT at Mt
Hopkins Arizona These data can b e obtained from Archives of IAU Commission as
le of unpublished photometry see Krisciunas and Guinan In Figure we show
the p ower sp ectrum of the V band data from ve years ago The least squares phase of the
Figure Data by Guinan and McCo ok from phased with ephemeris derived
from the data The mean value of V is slightly brighter
than the mean value obtained from the more recent photometry obtained at Mauna
Kea V
data from an ep o ch of is within the errors equal to
the phase of the data In Figure we show the data phased with the
ephemeris derived from the most recent data but folded with the full orbital p erio d
just in case one side of the primary app ears di erently than the other One can see
graphically that the ephemeris has not changed The photometric amplitude derived
from the V band data is mmag with a go o dness of t of mmag
for a single observation B band and U band data taken in yield amplitudes of
and mmag resp ectively
A tentative piece of con rming evidence that we are seeing the larger pro jected area
of an ellipsoidal star every half orbit comes from the orbital determination We should
see the minimum light when either of the visible star s smaller sides is facing us when
the orbital phase is or Between the sp ectroscopically derived ep o ch of maximum
velocity and an ep o ch of minimum light of HJD the di erence in time
divided by Gri n s orbital p erio d gives orbits Since the fractional part
of this number is close to it is entirely consistent with the notion that the visible
comp onent of Cam is tidally distorted by a less massive unseen comp onent This could
b e greatly reinforced by a new sp ectroscopic determination of the orbital phase
It is likely that the published luminosity class of Cam is wrong It may b e a subgiant
not a main sequence star Given the mass function an assumed mass of M for the
primary and a range of masses for the secondary we attempted to mo del the ellipsoidal
nature of the primary and found that there is no solution if the primary is the size of a
main sequence early A type star R R However if the primary has R R
a photometric range of mmag can b e obtained Given the primary s pro jected
1
rotational rate of km sec if R R the rotational p erio d could equal the orbital
p erio d This tidal lo cking is not unexp ected If sin i exp ected for a photometrically
variable ellipsoidal star the mass of the secondary is M
Roman includes Cam in her list of probable members of the Ursa Ma jor
8
stream There is a problem with this The age of the UMa cluster is ab out
years Wielen So derblom A M star such as Cam would have a main
sequence lifetime an order of magnitude longer than this If Cam is indeed a subgiant
it is much to o old to b e a member of the UMa stream
We note that the secondary we have b een discussing is not the m companion
v
discovered by Dembowski listed by Aitken and more recently observed at
00
by McAlister et al via sp eckle observations Cam also has an m
v
00
companion at
The HIPPARCOS parallax when it b ecomes available will allow many of parameters
of this system to b e more accurately determined
Acknowledgments We thank the University of Hawaii Institute for Astronomy for
telescop e time on the m telescop e at Mauna Kea Some information was obtained
from the simbad data retrieval system a data base of the Astronomical Data Centre
in Strasb ourg France D Osterbro ck provided some other useful information and com
ments KK and PP thank the Joint Astronomy Centre for observing supp ort MR s
observing exp enses were paid for by a University of Hawaii at Hilo fund endowed by
William Albrecht
R A CROWE
K KRISCIUNAS M ROBERTS
Joint Astronomy Centre Department of Physics
N A oh ok u Place and Astronomy
University Park Hilo University of Hawaii at Hilo
Hawaii USA West Kawili Street Hilo
kevin jach hawaii edu Hawaii USA
E F GUINAN K D LUEDEKE
G P McCOOK Giddings Avenue NE
Villanova University Albuquerque New Mexico USA
Department of Astronomy
P POBOCIK
Villanova Pennsylvania USA
P O Box Keaau
R F GRIFFIN Hawaii USA
The Observatories Madingley Road
Cambridge CB HA UK
References
Aitken R G New General Catalogue of Double Stars within of the North Pole
Washington D C Carnegie Institution
Harp er W E J R Astr Soc Canada
Harp er W E Publ Dom Astrophys Obs
Krisciunas K and Guinan E IBVS No
Lucy L B and Sweeney M A Astronomical Journal
McAlister H A Hartkopf W I Sowell J R and Dombrowski E D Astro
nomical Journal
Roman N G Astrophys J
So derblom D Astronomical Journal
Wielen R Mitteilungen der Astr Gesel lschaft No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
COMPLETE CCD U B V R I LIGHT CURVES OF THE
SHORT PERIOD ECLIPSING BINARY V LYRAE
The th magnitude variable V Lyrae was discovered by Ho meister who
classi ed it as an RR Lyrae type star but gave no p erio d No further work was done
for almost two decades until Galkina and Shugarov conducted a photographic
study which indicated that V Lyr is actually a Beta Lyrae type eclipsing binary
with an orbital p erio d of ab out hours Andronov and Richter con rmed
this conclusion while also noting an unusual di erence b etween the heights of the max
ima They suggested that V Lyr is a semi detached system undergoing vigorous
mass transfer as evidenced by a hot sp ot on the mass accreting comp onent Kaluzny
presented V I photo electric light curves and gave U B V standard mag
nitudes for some particular phases He listed three times of minimum light and es
timated the comp onents to b e of early K sp ectral type Later he Kaluzny
published photo electric V I light curves as well as one primary ep o ch of min
imum light Shugarov et al presented photo electric U B V light curves ac
cumulated over four observing seasons listing standard magnitudes at key
phases They suggested that the secondary is accreting matter and give estimates of K
V and K V for the primary and secondary comp onents resp ectively Nations et al
indicated that they have B V R I light curves and some preliminary mo dels Figure
Figure
Table
Star RA DEC
h m s
V Lyrae
h m s
Comparison
h m s
Check
Table
JD Hel Cycles O C O C
Our present U B V R I CCD light curves of V Lyrae were obtained as part of
our ongoing study of compact solar type eclipsing binaries The observations were made
on June inclusive and at Kitt Peak National Observatory KPNO
Arizona A Tektronix Te K chip and CCD camera system was used in conjunction with
the m re ector Between and observations were made in each passband
A CCD image of the eld is shown in Figure The variable comparison and check
stars are designated as v c and k resp ectively with co ordinates of each given in Table
Four new precise ep o chs of minimum light were determined from the observations made
during primary eclipses Several secondary were also calculated but were later removed
from our p erio d analysis due to severe distortions in the light curve around the secondary
eclipse phase The bisection of chords technique was used to determine all ep o chs
of minimum light These new primary minima are listed in Table In Table and
throughout the pap er values are accompanied by their probable errors in parentheses
The recent ep o chs of photo electric and CCD minima were introduced into a least
squares solution to obtain a new linear ephemeris which b est represents the present ob
servations
d
JD Hel Min E
The O C residuals calculated from equation are listed as O C in Table I I We
then calculated a quadratic ephemeris by introducing all available times of minimum light
and times of lowlight from Galkina and Shugarov and Andronov and Richter
into a least squares quadratic solution
d d
JD Hel Min E E
The quadratic term is statistically signi cant at greater than the sigma level This
negative term would indicate that the secondary less massive comp onent is the accretor
The residuals calculated from equation are listed in Table as O C
The standardized B V R I light curves of V Lyrae as de ned by their individ
c c
ual observations are shown in Figure as di erential magnitudes variable comparison
versus phase The analysis of the observations is in progress
Jamison D GRAY
Ronald G SAMEC
Brian J CARRIGAN
Department of Physics and
Astronomy
Millikin University
Decatur Illinois USA
Visiting Astronomer Kitt Peak National Observatory National Optical Observato
ries which are op erated by the Asso ciation of Universities for Research in Astronomy
Inc under contract with the National Science Foundation
References
Andronov I L and Richter G A AN
Galkina M P and Shugarov S Yu Variable Stars
Ho meister C AN
Kaluzny J AJ
Kaluzny J AA
Nations H L Bradstreet D H Guinan E F and Laurenzano J BAAS
Shugarov S Yu Goranskij V P Galkina M P and Lipunova N A IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
CCD PHOTOMETRY OF SIX FAINT CATACLYSMIC VARIABLES
Photometric observations of several CV candidates were obtained using the CCD cam
era on the Danish m telescop e at the Europ ean Southern Observatory in June July
Table Di erential instrumental magnitudes were then derived relative to nearby
comparison stars on the same CCD image The ma jor goals were to con rm or reject
the CV nature of the targets and to search for orbital variability and eclipses Detailed
analysis of interesting systems is published separately This notice presents results for six
ob jects
PG
This ob ject was classi ed as a CV showing a comp osite sp ectrum Green et al
Recent sp ectrophotometric observations Zwitter and Munari revealed no emission
lines or hot continuum It may b e that this ob ject is a misidenti cation as a CV b ecause
the photometry also showed no evidence of any variability
PG
This ob ject was also classi ed as a CV by Green et al The photometry showed
no indication of a typical CV light curve There was only a small decline in brightness
of ab out mag within three hours The small scatter of ab out mag rules out
ickering activity The ob ject is probably not a CV
NSV
Eggen lists this ob ject BPM as a probable variable white dwarf susp ect
A p ossible CV nature is assigned in the NSV catalogue The hour light curve shows a
slight increase in brightness by ab out mag with sup erimp osed ickering of ab out
mag There is no indication for a p erio dic mo dulation Nevertheless the ob ject is likely
to b e a CV
NSV
Haro and Luyten suggest this blue ob ject Var to b e an eruptive variable It
is listed as a p ossible CV in the NSV catalogue The and hour runs show typical
ickering activity with an amplitude of ab out mag Whereas during the rst night
the system remained nearly constant it brightened during the second steadily by ab out
mag The mean magnitudes on the two nights di er by ab out mag A p erio dic
variation longer than hours is therefore exp ected
CF Gru
Hawkins and Veron detected the variability of this blue ob ject and classi ed it
sp ectroscopically as a CV CCD photometry by Howell et al revealed hot sp ot
mo dulations with a p erio d of min and the presence of large ickering The present
data set shows generally the same b ehaviour but can b e b etter tted with a p erio d of
min Figure
Figure Di erential light curve of CF Gru in integral light The measurements taken
on June are folded with a p erio d of min phase arbitrary This p erio d
represents the present observation b etter than the min given by Howell et al
Figure Di erential photometry of Hawkins V obtained in integral light on July
A rep eatable mo dulation with a p erio d of min is present At UT the
integration time of s was changed to s
Table Observing log Start is the time for the midp oint of the rst exp osure The
observation interval also includes gaps due to any interruption of the exp osure series
Magnitudes are in B except for the NSV ob jects where the values from the NSV
catalogue are given Observations were p erformed in integral light except for NSV
where a Johnson B lter was used
Ob ject Date Start Interval Int Time Frames Mag
UT h s
PG Jun
PG Jul
NSV Jun
NSV Jun
Jun
CF Gru Jun
Hawkins V Jul
Hawkins V
Based on its outburst b ehaviour Hawkins classi ed this ob ject as a CV
The hour photometric run shows evidence for a p erio dic mo dulation masked by strong
ickering activity Figure A p erio dogram analysis yielded a p ossible p erio d of
min Further the light curve shows a steady decrease of ab out mag over the entire run
thus indicating that the system was probably observed during a decline from outburst
R HAEFNER
Universit ats Sternwarte
Scheinerstr
M unchen
Germany
References
Eggen O J ApJ
Green R F Schmidt M Lieb ert J ApJS
Haro G Luyten W J TTB No
Hawkins M R S Nature
Hawkins M R S Nature
Hawkins M R S Veron P A A
Howell S B Szkody P Kreidl T J Dobrzycka D PASP
Zwitter T Munari U A AS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
THE FIRST PERIOD CHANGE DISCOVERED IN
THE BRIGHT ALGOL SYSTEM UV LEONIS
BAV Mitteilungen No
The UV Leo system consists of two detached main sequence stars of solar type and
nearly equal prop erties m m R R solar masses and radii ac
cording to Giuricin et al Ho meister discovered the variability and the system
has so on classi ed as an eclipsing binary by Jensch The depth of the primary and
the secondary minima is nearly equal nevertheless some small night to night uctuation
in the light curve has b een observed probably due to intrinsic variability of one or
b oth of the comp onents The magnitude outside eclipse is given as V by Popper
so the system is fairly bright
The correct p erio d very near to days was rst derived by Schneller Mc
Cluskey demonstrated that the p erio d of UV Leo had b een constant since at least
This nding can also b e extended back to on base of data from sky patrol
plates given by Gap oschkin The p erio d change claimed by Ahnert around the
year could not b e con rmed Elements published by Rafert also cited in the
th edition of the GCVS describ e the light variations well from up to the early
eighties
d
Hel Min I J D : E
At N urnberg Observatory UV Leonis has b een observed photo electrically since
We continued monitoring the system using a m Cassegrain telescop e
equipp ed with a P phototub e and V lter Five new times of minima determined from
the light curves are included in Table which lists all available times of minima from
the literature and their O C residuals computed against elements The data given
by Soliman et al was not included since it seems to su er from systematic error Figure
Table
Hel JD O C E Observer Hel JD O C E Observer
1 1
days cycle and Ref No days cycle and Ref No
Perek Szczepan
Perek Broglia
Perek Szczepan
Perek Herczeg
Perek McCluskey
Perek McCluskey
Perek McCluskey
Perek McCluskey
Perek McCluskey
Perek McCluskey
Piotrowski McCluskey
Perek McCluskey
Perek McCluskey
Piotrowski M uller
Perek Krausser
Wallenquist Pohl
Wallenquist Bickel
Nason Kurutac
Nason Ibanoglu
Szczepan H olzl
Wellmann Grampp
Wellmann Akinci
Wellmann Eb ersb erger
Wellmann Eb ersb erger
Wellmann Besold
Wellmann Eb ersb erger
Wellmann Ertan
Wellmann Chwastek
Wellmann Bo de
Wellmann Elias
Wellmann Diethelm
Wellmann Fernandes
Fracastoro Ells
Fracastoro Diethelm
Fracastoro Diethelm
Fracastoro Wunder
Broglia Wieck Wund
Broglia Hudecek
Broglia Paschke
Broglia Bl attler
Broglia Diethelm
Broglia Wunder
Broglia Diethelm
Broglia Wunder
Szczepan Wund Traub
From the O C diagram in Figure it is obvious that the p erio d of UV Leonis increased
at around JD This is the rst reliable p erio d change in the system discovered
yet Calculating new elements for the time since JD the least squares metho d
yields
d
Hel Min I J D : E
E WUNDER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
N urnberg Observatory
Regiomontanusweg
N urnberg
Germany
References
Ahnert P Mitt Ver and Sterne Sonneberg Heft
Braune W Mundry E BAV Mitteilungen No
Broglia P Mem Soc Astr Ital
Broglia P Journal des Observateurs
Diethelm R BBSAG Bul l No
Diethelm R BBSAG Bul l No
Diethelm R BBSAG Bul l No
Diethelm R BBSAG Bul l No
Eb ersb erger J Pohl E Kizilirmak A Inf Bul l Var Stars No
Gap oschkin S Astrophys Journal
Giuricin G Mardirossian F Mezzetti M Astron Nachrichten
Hanzl D Inf Bul l Var Stars No
Herczeg T Ver o der Univ Sternw Bonn No
Ho meister C Astron Nachrichten
Isles J E Brit Astr Assoc Var Star Section Circ No
Jensch A Astron Nachrichten
Kizilirmak A Pohl E Inf Bul l Var Stars No
Kizilirmak A Pohl E Inf Bul l Var Stars No
Lo cher K BBSAG Bul l No
Lo cher K BBSAG Bul l No
Lo cher K BBSAG Bul l No
McCluskey G E Astron Journal
Nason M E Mo ore R C Astron Journal
Perek L Contr Astr Inst Brno No
Piotrowski S L Strzalkowski A Acta Astron Ser C
Pohl E Evren S T umer O Sezer C Inf Bul l Var Stars No
Pohl E G ulmen O Inf Bul l Var Stars No
Pohl E Kizilirmak A Astron Nachrichten
Pohl E Kizilirmak A Inf Bul l Var Stars No
Pohl E Kizilirmak A Inf Bul l Var Stars No
Pohl E Kizilirmak A Inf Bul l Var Stars No
Pohl E Kizilirmak A Inf Bul l Var Stars No
Popper D M Astrophys Journal
Rafert J B Publ Astron Soc Paci c
Schneller H Astron Nachrichten
Soliman M A Hamdy M A Mahdy H A Inf Bul l Var Stars No
Szczepanowska A Acta Astron
Wellmann P Zeitschrift f ur Astrophysik this pap er
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
HD AN UU Her SPECTRUM VARIABLE
The star HD V Cas is a yellow semiregular variable of small amplitude
observed recently by Zsoldos who showed that it b elongs to the small group of UU
Her type variables which comprises UU Her V Cas and p erhaps BL Tel
The star has b een classi ed as G Iab Bidelman G Ia Nassau and Morgan
and G Ia Keenan and McNeil The latter classi cation is based up on plates
taken in August and December and July The sp ectrum is
repro duced on plate N of Keenan McNeil Atlas
Figure The sp ectrum of HD or a rapid orientation the Paschen lines from P to
P are marked with black triangles and the Paschen lines blended with Ca I I are
marked with triangles For xing the sp ectral type the gure should b e compared with
those contained in An Atlas of the infrared sp ectral region by Y Andrillat C
Jaschek M Jaschek accepted for publication in AA Suppl
A CCD sp ectrum of this ob ject was obtained at the Observatoire de Haute Provence
in September in the infrared region for the purp ose of establishing an Atlas in the
A region The disp ersion of the sp ectogram is A mm By comparison with
other MK standards it turns out that the sp ectrum is now de nitely earlier than G we
have classi ed it as F Ia It seems thus very likely that the star is a sp ectrum variable
and further observations of this star and of the group members are highly desirable
?
M JASCHEK
?
C JASCHEK
??
P KEENAN
???
N GINESTET
???
J M CARQUILLAT
?
Observatoire de Strasb ourg France
??
Ohio State Observatory US
???
Observatoire Midi Pyr en ees France
References
Bidelman W P Ap J
Keenan P C and McNeil R C An Atlas of the sp ectra of the co oler stars
Ohio State University Press
Nassau J J and Morgan W W Ap J
Zsoldos E AA
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NEW TIMES OF MINIMA OF ECLIPSING BINARIES
VW Cep U Cep AND RZ Cas
VW Cephei HD BD SAO is a well observed active W UMa
type binary Its regular photometry was b egun in at Szeged Observatory The
aim of this long term pro ject is twofold First the light curve of the system shows
temp oral variation on short timescales hours Kreiner Winiarski as well as
long timescales years Bradstreet Guinan years Karimie Second
VW Cep is a member of a triple system Hershey its p erio d is mo dulated by the
light time e ect but the p erio d variation of the system is quite complex A detailed
analysis of the p erio d variation has b een presented recently by Lloyd Watson Pickard
and Vink oet al
Di erential photo electric photometry of VW Cephei was carried out on nights in
September with a cm Cassegrain telescop e and an Optec SSP A photo electric
photometer The light curve in Johnson V and B bands was obtained and it is presented
in Figure The comparison star was HD which was used previously by many
observers
Table contains the helio centric times of minima calculated from parab olic least
squares t to the b ottom of the minima The O C values were derived from the ephemeris
given in the th edition of GCVS The O C of secondary minimum was calculated so
that the time of the secondary minimum was exp ected at the phase
Our minimum times show that the p erio d decrease of the system continues in agree
ment with the conclusion of previous analyses by Lloyd Watson Pickard and
Vink oet al The asymmetry of the light curve do es not exceed mag which
suggests that the next activity maximum prop osed by Bradstreet Guinan has
not o ccurred yet
The Algol type eclipsing binaries RZ Cas and U Cep were measured with an un ltered
ST CCD camera attached to a Telemator refractor Only one minimum was observed in
b oth cases The comparison star of U Cep was HD while in the case of RZ Cas a
nearby star GSC V was used as comparison
The helio centric times of minima of U Cep and RZ Cas are listed in Table The
O C values are computed from the ephemeris given in the GCVS
In the case of U Cep simultaneous BV photo electric and CCD photometry was made
The comparison of data strongly suggests that the un ltered CCD measurements are
useful for detection of light minima of eclipsing binaries Since the duration of the totality
was longer than day the observed eclipse was an undisturb ed one according to the
de nition of Crawford Olson Figure shows a part of the O C diagram of U
Cep computed using our new time of minimum and some recent measurements Olson et
al Sato Nishimura Surkova Burnett Etzel Olson From the
slop e of the tted line the following ephemeris has b een derived
H el J D M inI E
Figure Di erential B and V light curve of VW Cephei
Figure O C diagram of U Cephei
Table Minimum times of VW Cephei
Min Hel JD Type O C days
I
I
II
I
Table
Star Min Hel JD type O C days
U Cep I
RZ Cas I
Using the p erio d values given in the GCVS and in this pap er the rate of the p erio d
9
increase during the last days was also calculated it is dP P day day
A detailed analysis of p erio d variation of RZ Cas has b een presented recently by
Heged us Szatm ary Vink o They showed that the p erio d variation contains
four p erio dic comp onents However it seems that our new time of minimum do es not
agree with the prediction of their O C curve tting
The list of individual observations is available via e mail from l kiss physx u szeged hu
Internet
The fruitful discussions with Drs K Szatm ary and J Vink o are gratefully acknowl
edged This work was partly supp orted by OTKA Grants No T T and F
and Szeged Observatory Foundation
G KASZAS
L L KISS
Dept of Optics
J GAL
JATE University
Astronomical Observatory and
Szeged D omt er
Dept of Exp erimental Physics
H Hungary
JATE University
Szeged D omt er
H Hungary
Internet L Kiss physx u szeged hu
References
Bradstreet D H Guinan E F in A Decade of UV Astronomy with IUE ESA
SP Vol p
Burnett B J Etzel P B Olson E C Astron J
Crawford R C Olson E C Publ Astron Soc Paci c
Heged us T Szatm ary K Vink o J Astrophys Sp Sci
Hershey J L Astron J
Karimie M T Astrophys Sp Sci
Kreiner J M Winiarski M Acta Astr
Lloyd C Watson J Pickard R D IBVS No
Olson E C Hickey J P Humes L Paylor V IBVS No
Sato F Nishimura A IBVS No
Surkova L P IBVS No
Vink o J G al J Szatm ary K Kiss L IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
THE ORBITAL PERIOD OF THE ROSAT CATACLYSMIC
VARIABLE S COMAE BERENICES
S Com the optical counterpart of the ROSAT X ray source RX J
was by observations on Sonneb erg photographic plates not only found to have high
m m
and low brightness states like magnetic cataclysmics there could b e noticed
m
also an eruption : similar to that of a dwarf nova Richter and Greiner
The only star hitherto known to show a similar b ehaviour is V Oph Wenzel and
Splittgerb er May b e that S is related to this ob ject whose exact physical
nature is however still p o orly known
Additionally large uctuations in the ab ove mentioned states of high minimum light
and apparently also in the rare low states were observed We therefore decided to carry
out time resolved di erential photometry of S at the Sonneb erg cm re ector
by means of a CCD camera of Wright Instruments Ltd type EEV Three
night series of rep eated exp osures in the R band led to the detection of an eclipsing
variability The elements of brightness variations are
d
Min hel J D : E
Figure shows the greater part of our series of May m means the
magnitude di erence against one of the our comparison stars The R band amplitude of
the eclipses is ab out mag and their duration approximately min In the following
table the ve minima observed in the three nights of and the deviations from the
ephemeris are listed
HJD E O C
d
:
Figure gives all eclipse observations folded by the ab ove elements
Interestingly the p erio d length is just at the lower b oundary of the well known p erio d
d d
gap of cataclysmic variables : :
Most ob jects with p erio d lengths similar to that of S are either SU Ursae Maioris
or AM Herculis stars S however is an outstanding ob ject and deserves further attention
Figure Geo centric observing time s after b eginning of the current Julian Day
Figure
Acknowledgements We are most grateful to J Greiner Max Planck Institut f ur Ex
traterrestrische Physik Garching for stimulating the search for optical variability of
ROSAT sources Our work was partly supp orted by funds of German Bundesministerium
f ur Forschung und Technologie under contract nos A A W W and S
G A R
W WENZEL R SCHWARTZ
G A RICHTER Gleimstrasse
R LUTHARDT D Berlin
Sternwarte Germany
D Sonneb erg
Germany
References
Richter G A and Greiner J Pro c of the Padova Abano Conference on Cata
clysmic Variables in the press
Wenzel W and Splittgerb er E Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
A NEW SEMIREGULAR VARIABLE S IN CORONA BOREALIS
When searching for an optical counterpart of the BATSE gamma ray burst source
h m
B : UT at the improved p osition Greiner on a Sonneb erg Sky Patrol
plate taken by B Fuhrmann hours b efore eruption I discovered a new semiregular
variable at the following p osition within the error b ox of the gamma source
h m 0
:
The ob ject is easily lo calized by its brightness and red colour on the POSS sheets
no
On a sample of patrol plates taken b etween and by H Huth I found an
m
average cycle length of days and amplitude of mag in the photographic band :
m
: Mt Wilson system of Selected Area The light curve is partly sine shap ed
partly characterized by sharp er minima and partly more irregular On a Sonneb erg
cm Schmidt camera ob jective prism plate taken April UT by W
G otz the sp ectral type can b e determined as M
There is at present no hint that either this variable or one of the variables formerly
detected in the region of the error b ox e g X CrB RT Bo o Z CrB can b e physically
related with the gamma ray burst source
This work has b een supp orted by funds of the German Bundesministerium f urForschung
und Technologie under contract no SO A
W WENZEL
Sternwarte
D Sonneb erg
Germany
Reference
Greiner J unpublished
ERRATUM
In the No issue of the IBVS all ephemerides of VW CVn refer to normal maxima
and not Min I as stated erroneously in the text The authors of that note and editors
of the IBVS are grateful to Dr N Samus for calling their attention to this inconsistency
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
THE ELLIPSOIDAL VARIABILITY OF HR
The Eighth Catalogue of the Orbital Elements of Sp ectroscopic Binary Systems Bat
h m s m
ten et al lists the star HR V
d
as a single lined sp ectroscopic binary with a p erio d of This is based on sp ec
troscopy due to Abt
HR was included in a recent campaign of p otential ellipsoidal variables Obser
vations have b een made with the Devon Astronomical Observatory m telescop e using
a recently installed CCD imaging system Photometry was carried out on HR over
the nights January and February The data consist of V lter
observations Integrations were seconds at approximately minute intervals
in phase
m m
The star SAO V was used as a comparison with SAO V serving
d
as a check star The data were phased with the p erio d given by Abt and
computed from his ep o ch of maximum radial velocity T JD The results
were averaged in equal phase bins The data as presented have not b een transformed
from the lo cal to the standard UBV system
A Fourier series of the form
X
l A A cos B sin
i i i i
where l is ux and is the orbital phase measured from the time of maximum velocity was
tted to the data Linear regression analysis was used to p erform a Fourier least squares
t for the rst terms The co e cients along with standard errors are presented in Table
The residual error in the t is roughly in ux which is typical of scatter in the
observations The Fourier series is plotted in Figure along with the data The dominance
of the cos term supp orts the suggestion that HR is an ellipsoidal binary system
and the phase relationship b etween the photometric and sp ectroscopic data is consistent
with that interpretation
A complete discussion of this system which includes analysis of the sp ectroscopic data
will b e published as part of the M Sc thesis of E S
Table
Fourier Co e cents
A A A B B
standard error of co e cients
Figure V lter ux observations of HR phased in bins of width Phasing is
d
with resp ect to a p erio d of and from ep o ch date T JD The
solid line represents a least squares fourth order Fourier t to the data
E STEINBRING
steinb stellar phys ualberta ca
D P HUBE
Department of Physics
University of Alb erta
Edmonton Alb erta
Canada T G J
B E MARTIN
The King s University College
th Street
Edmonton Alb erta
Canada T B H
References
Abt H J Astr J Suppl Ser
Batten A H Fletcher J M and MacCarthy D G Eighth Catalogue of the Or
bital Elements of Spectroscopic Binary Systems Publ of the Dom Astr Obs Victoria
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NARROWING THE MAIN SEQUENCE MASS GAP
Andersen s compilation of stellar masses contains stars with masses b etween
solar masses and the long known masses of the M dwarf YY Gem m namely
the secondary of FL Lyr G m and the comp onents of HS Aur G K
The discussion of visual binaries by Henry and McCarthy contains only one
star with a mass in this range with comparable accuracy Alpha Cen B K V
In recent years a program has b een undertaken at the Lick Observatory with the
primary aim of helping to obtain masses of additional main sequence stars in the mass
range to m The observations consist of sp ectra of eclipsing binaries which on the
basis of existing information may contain at least one detached main sequence comp onent
of sp ectral type G or K To date sp ectra have b een obtained of approximately eclipsing
binaries and the most promising ones are given high priority on the observing program A
progress rep ort giving preliminary results as of ab out years ago has b een published
Popper as have de nitive analyses of two of the systems RT And and CG Cyg
Popper These two pap ers discuss the nature of the program in some detail
An up dated progress rep ort is given in Table It contains results based on limited
3
material for those systems for which a provisional value of msin i of at least one com
p onent is equal to or less than solar masses Alpha CrB and V Tau see Popper
are binaries containing a star having less than one solar mass not observed in this
program The table includes ve systems ZZ UMa HP Aur E HD
and BH Vir for which this is the rst announcement of new mass determinations The
very provisional nature of the results is to b e emphasized The systems are listed in order
of decreasing p erio d Several of the provisional results in Table are for systems UV Psc
BH Vir CG Cyg RT And UV Leo that have b een previously observed with much lower
resolution than that employed in this program References are in Batten et al
The sp ectral types listed in Table are rough values based on the strengths of the
Na D lines which are sensitive to temp erature The types are mean values weighted
according to the luminosities of the comp onents and to the intrinsic strengths of the D
lines The apparent magnitudes presumably in the V band are from a variety of sources
References to binaries not having constellation names are as follows HD Kissling
et al HD Marschall et al E Summers et al The
ephemerides of these recently discovered eclipsing binaries are not rmly established I
have found it necessary to subtract from phases of HD computed with the
ephemeris given in IBVS The ephemeris given in IBVS for E do es
not t my velocities An improved ephemeris is JD min E
3
Table Detached eclipsing binaries with provisional values of msin i
solar masses or less
? 3 3
Binary Period d V mag Type m sin i m sin i
1 2
ZZ UMa G
HP Aur G
DU Leo F
HD G
E K
UV Psc G K
CV Bo o G
BH Vir F
HD F
CG Cyg K
RT And F
UV Leo G
?
Types are means weighted according to the relative luminosities of the comp onents
and to the intrinsic strengths of their Na D lines
The sp ectroscopic material on which the preliminary results summarized in Table
have b een based is obtained with the Hamilton echelle CCD sp ectrometer on the m
Shane telescop e of the Lick Observatory Vogt This instrument is proving to
1
b e ideal for the purp ose resolution approximately scale Amm in the visual
region S N in the continuum of roughly p er resolution element for an exp osure of
ab out minutes on a star of th magnitude Details of the cross correlation pro cedure
employed for the velocities IRAF program are given in Popper and Popper and
Jeong
The principal purp ose of presenting these preliminary results at this time is to direct
the attention of photometric observers to these imp ortant systems Without reliable
photometric observations and analysis the sp ectroscopic results will have limited value
The short p erio ds of most of these detached systems are noteworthy the shorter the
p erio d the greater the likelihoo d that eclipses will o ccur This e ect also p ermits coverage
of the light curve in a relatively short interval of time a favorable situation for observers
On the other hand short p erio ds are asso ciated with larger rotational velocities which in
turn favor intrinsic variations asso ciated with star sp ots and p erhaps other manifestation
of stellar activity For this reason it is essential that a complete light curve b e observed
in a relatively short interval and that the coverage b e rep eated several times over a p erio d
of a few years RT And Zeilik et al and CG Cyg Zeilik et al are examples
of systems for which rep eated photometric coverage by a variety of observers has led
to consistent basic solutions of the light curve as well as to evaluations of star sp ot
parameters While such numerous observations as in the cases of RT And and CG Cyg
are ideal considerably less frequent coverage of the light curves of the systems of Table
should lead to results of adequate reliability
Photometry should b e carried out in a photometric system carefully tied to a standard
system The Str omgren intermediate band v b y system has the advantage of giving
information on metallicity which is of considerable imp ortance in interpreting the stellar prop erties in terms of evolutionary mo dels as discussed by Andersen for example
It is not p ossible to evaluate metallicity directly from sp ectra of rapidly rotating stars
None of the binaries is particularly faint and a number of them can b e observed with
adequate precision not worse than mag with mo dest equipment
Pending more nearly de nitive sp ectroscopic orbits and photometric solutions for most
of the systems of Table it app ears that we may indeed b e able to narrow the gap in
the masses of detached main sequence stars to the as yet un lled interval to solar
masses One may hop e that further discoveries some of those represented in Table are
quite recent will add signi cantly to our store of stellar masses in this mass range Con
centrated photometry on any or all of these binaries would provide a ma jor contribution
to this endeavor
Daniel M POPPER
Department of Astronomy
University of California
Los Angeles CA U S A
internet
p opp er b onnie astro ucla edu
References
Andersen J Astron Astrophys Rev
Batten A H Fletcher J M and MacCarthy D G Publ Dom Astrophys
Obs
Henry T J and McCarthy D W Astron J
Kissling W M Blow G L and Gilmore A C IBVS No
Marschall L A Gauthier C P Nations H L Taylor B W and Huard T L
IBVS No
Popper D M Astrophys J Lett L
Popper D M Astron J
Popper D M and Jeong Y C Publ Astron Soc Paci c
Summers D L Zeilik M Jaderlund E Ho epp e G and Collins A IBVS
No
Vogt S S Publ Astron Soc Paci c
Zeilik M Cox D A DeBlasi C Rho des M and Budding E Astrophys J
Zeilik M Gordon S Jaderlund E Ladlow M Summers D L Heckert P A
Budding E and Banks T S Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
UBV LIGHT CURVES OF THE NEAR CONTACT
BINARY AK CANIS MINORIS
In our study of the eccentric eclipsing binary EEB candidates of Heged us we
h m s
obtained UBV photo electric light curves of AK Canis Minoris R A :
D AK CMi BD AN P SVS was
discovered by Ho meister Notni published a photographic light curve and
determined a p erio d of d He states that the shallow secondary eclipse we measure
mag in B o ccurred at phase Given the high scatter and the sparse coverage
of his light curve this result is highly questionable Strohmeier et al includes a
nder chart in his study Robb and Mo at give two precision ep o chs of primary
minima and one of a secondary minimum We nd that their secondary eclipse o ccurs
at phase Shaw includes AK CMi in his list of near contact binaries In all
some timings of minimum light are found in the literature or in the BAV data base
The present observations were taken on February inclusive at Lowell
Observatory Flagsta Arizona with the National Undergraduate Research Observatory
m re ector A thermo electric co oled PMT was used with Johnson UBV lters Two
h m s
nearby stars were used as comparison R A : D
h m s
and check R A : D The comparison star was
an excellent color match to the variable with the B V and the U B averaging
and resp ectively
Figure Period b ehavior of AK CMi as shown by the calculated from the quadratic ephemeris
Figure Light curves of AK CMi as de ned by the individual observations
Two mean ep o chs of minimum light were calculated from one secondary and one pri
mary eclipse The bisection of chords metho d was used Our ep o chs were JD Hel Min I
and JD Hel Min I I From the densely
packed data of the past years we determined the following improved ep emeris
d
JD Hel Min I : E
The O C s calculated from this ephemeris suggest that AK CMi is undergoing a
continuous p erio d decrease Because of this we calculated the quadratic ephemeris
d
JD Hel Min I : E E
The O C s generated from the rst two terms of this equation are shown in Figure
overlain by a curve generated by the quadratic term In these calculations we weighted the
precision ep o chs as and the photographic and visual timings as We used equation
to phase our observations These equations indicate that our Min I I o ccurred at phase
to within the errors We b elieve that AK CMi is not an EEB The app earance of the
light curves ab out the secondary eclipse supp orts this conclusion
The light curves of AK CMi de ned by the individual observations are shown in Figure
as mag vs phase Our preliminary light curve solution indicates that the comp onents
are in a near contact semi detached con guration with the llout of the primary comp o
nent b eing and a comp onent temp erature di erence of K The complete
analysis of the observations are underway and will app ear elsewhere
?
RONALD G SAMEC
RICHARD J McDERMITH
BRIAN J CARRIGAN
Dept of Physics and Astronomy
Millikin University
Decatur Il
USA
?
Visiting Astronomer Lowell Observatory Flagsta Arizona
References
Heged us T CDS Bul letin
Ho meister C AN
Notni P MVS
Robb R M Mo at J D BAAS
Shaw J S Mem Soc Astron Ital
Strohmeier W Kipp enhahn R and Geyer E Bamberg Kl Ver o No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
ECLIPSE OBSERVATIONS OF EQ Tau
h m s 0 00
EQ Tau G V J is a p o orly studied W UMa
eclipsing binary with a p erio d of days This system is on the AAVSO list of eclipsing
binaries Baldwin and Samolyk but to our knowledge has had no previously pub
lished light curve or ephemeris The AAVSO reference rep orts eclipse minima observations
chie y by G Samolyk during the p erio d JD to An O C
plot using the AAVSO observations indicates that the published p erio d of days
Brancewicz and Dworak was slightly long but it was not clear whether the p erio d
was constant or whether there was a small p erio d derivative
The present note describ es CCD photometry of EQ Tau done using the University of
Iowa Automated Telescope Facility lo cated in Iowa City IA The system consists of an
00
cm refractor a Sp ectrasource HPC CCD camera format binned pixels
h m s
p er pixel and a Johnson R band lter We used the nearby GSC stars at
0 00 h m s 0 00
and J as check and comparison stars resp ec
tively Each observation consisted of second exp osures of a eld containing EQ Tau as
well as the check and comparison star This cycle was rep eated every minutes for several
hours each night The di erential ap erture photometry was p erformed by an automated
pro cedure after aligning all images to a common stellar reference No air mass or color
corrections were applied The system was observed during three ep o chs Dec Feb
Feb By combining all three ep o chs we obtained the nearly complete light
curve as shown in Figure The minimum at phase o ccurred at helio centric Julian
date Note the magnitude depression present b etween phase
in b oth February ep o chs only We b elieve this is not an artifact and may have
b een due to an active region on the stellar surface which developed since the December
observations
The O C measurements available from the AAVSO compilation clearly showed that
the previously available ephemeris
JD E
min
was slightly in error although it was unclear whether the deviation could b e b etter t
with a linear or a quadratic dep endence The present observations are in b etter agreement
with a linear t and new ephemeris given by
JD E
min
where the p erio d uncertainty represents the con dence b ounds A plot of the AAVSO
observations along with the minimum rep orted in this note is shown in Figure
Interesting parties can obtain the raw photometry data from the authors at the fol
lowing e mail addresses rlm astro physics uiowa edu or uwb astro physics uiowa edu
Figure Light curve of EQ Tau The depression evident near phase seen during
February may have b een caused by a starsp ot
Figure O C plot for EQ Tau using JD N where N is the
cycle number A least squares linear and quadratic t is also shown The linear t
represents the new ephemeris N
This research has b een supp orted by the Iowa Space Grant Consortium and the Na
tional Science Foundation We have also made use of the Simbad database op erated at
CDS Strasb ourg France
W R BENBOW
R L MUTEL
Van Allen Observatory
Dept Physics and Astronomy
University of Iowa
Iowa City IA
References
Baldwin M and Samolyk G AAVSO Observed Minima Timings of Eclipsing
Binaries No
Brancewicz H and Dworak T Acta Astron
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Konkoly Observatory
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May
HU ISSN
HD IS VARIABLE BUT IT IS
NOT A DELTA SCUTI STAR
m m s
Short p erio d variability of HD
a few arcminutes north of the globular cluster M was claimed by Yao Tong
here after YT on the basis of nights of photometry Their observations implied a
p erio d of ab out minutes YT also gave arguments that this star has mid A sp ectral
type using an estimate of the interstellar reddening of eld stars in the direction of M and
published UBV photometry They concluded that HD is a new Scuti variable
Even earlier Clementini suggested that this star is likely to b e variable b ecause
her BVRI photometry disagreed with previously published results
However the data of YT were acquired at Beijing Observatory lo cated at a lati
tude of so that YT could never observe the star at air mass values lower than
Moreover they neglected the sp ectral classi cation of HD from the Michigan
Sp ectral Catalogue Houk giving a sp ectral type of G V as well as the star s H
index of measured by Eggen Such a H value is not typical of a Scuti
star Finally YT nd their estimated U B to b e to o blue If they dereddened
the V R and V I colors of Clementini in the same way like the UBV
c c
photometry they would have found further inconsistencies On the other hand assuming
that HD is a G dwarf suggests that it is a foreground star relative to the ob jects
adopted for the determination of interstellar reddening and hence it could have lower
reddening
All this casts considerable doubt on the claim of YT that HD is a Scuti
star Therefore it was decided to re observe it in order to shed more light on its nature
Observations and reductions In March and April HD was observed
with the Mo dular photometer attached to the cm telescop e at the South African Astro
nomical Observatory a dedicated instrument for high precision photo electric photometry
Keeping in mind the short p erio d claimed for the star the choice of the observing tech
nique must b e considered carefully
In order to detect p erio ds shorter than one hour high sp eed photometric observations
can give excellent results e g Handler et al but this technique is not very useful
in the presence of sky transparency variations see Breger Handler Therefore
it was decided to acquire di erential photometry with two close comparison stars this
allows to comp ensate for transparency variations as well as to examine the data for p ossible
variability of the comparison stars the comparison star adopted by YT was HD
for which the Michigan catalogue gives a sp ectral type of A V Furthermore by using
close comparison stars the telescop e can very quickly b e moved from star to star
For these purp oses HD C and HD C A I I I were selected Both
ob jects are within less than arcminutes distance from the program star HD P
For each star a second integration in the V lter as well as a second integration for
sky background were made The stars were observed in the order C P C C P C
Figure Di erential time series photometry of HD lled circles HD
crosses and HD diamonds
Figure Amplitude sp ectra and sp ectral window of the data of Figure The panels
from top to b ottom show the sp ectral window of the data the amplitude sp ectrum of
the program star data as well as the amplitude sp ectra of the comparison star data
Table UBVR I photometry of the program and comparison stars
c c
Star V B V U B V R V I
c c
HD
HD
HD
Thus consecutive measurements of HD could b e obtained ab out every
seconds corresp onding to a Nyquist frequency of cycles p er day which is more
than su cient to detect a conjectured p erio dicity of minutes During the time series
photometric observations the air mass never exceeded As a further check of data
quality the E region standards E A V and E G V were measured at the
b eginning of each run
All data were corrected for dead time losses as well as for sky background and mean
extinction Mean zerop oints of all nights of observation considered together of P C and
C were calculated relative to each other and subtracted from the time series data The
zero p oint subtracted data are plotted in Figure where the variability of the program
star is evident It is also clear however that the light mo dulation o ccurs on a time scale
much longer than minutes Moreover Figure shows that only very small transparency
variations o ccurred during our measurements
It should also b e mentioned that the standard deviation of the zerop oints b etween the
comparison stars and the E region stars were comparable to the rms error of a single
measurement of the standard stars The rms errors of a single measurement of the data
displayed in Figure are mmag for HD mmag for HD but
mmag for HD
UBVR I photometry was also acquired for these three stars Table the transfor
c c
mation into the standard system was secured by measuring several E region standards
We conservatively estimate the rms errors with mag in V mag in B V and
V R as well as mag in U B and V I Note that HD is variable and
c c
therefore the results for this star must b e treated with caution
Analysis and discussion Since the photometric conditions were very stable during
our observations amplitude sp ectra can b e calculated for each star separately i e we do
not consider di erential data b etween the stars These amplitude sp ectra are shown in
Figure Insp ection of Figure again suggests that the time scale of the variability of
HD is longer than minutes it is at least several hours However the sp ectral
window is far to o complicated and the data are to o sparse to make a more de nite state
ment ab out the real time scale In order to examine the p ossibility that the low frequency
variability could mask shorter p erio d variations we have also calculated an amplitude
sp ectrum for the HD data after removing the nightly zerop oint variations once
again there is no hint for a minute p erio dicity
What kind of variable can HD b e Considering the UBVR I photometry in
c c
Table as well as uvby data for the star Handler we nd that it is unreddened
Hence it is far to o co ol to b e a Scuti star
Applying the calibration of Crawford we nd an absolute magnitude of M
V
Thus our results are p erfectly consistent with Houk s sp ectral classi cation of HD G V as well as with colors measured by Lee and Clementini
Due to the small amount of data we obtained we cannot pinp oint the cause of the
light variability of HD However we wish to emphasize that the star might b e in
teresting for researchers studying variability of solar type ob jects caused by starsp ots If
HD would b e a related ob ject then its amplitude is rather high note that Eggen
found the star to b e fainter than HD and it would b e one of the most
active solar type stars The photometric b ehavior of HD clearly requires a more
thorough study A sp ectrogram of the star with su cient resolution to examine it for
chromospheric emission or for a p ossible secondary sp ectrum would also b e useful
Summary and conclusions We showed that HD is an early G type main
sequence star which exhibits light mo dulation on a time scale of at least several hours
Contrary to a previous claim we demonstrated that it cannot b e a Scuti star it is far
to o co ol
It is suggested that authors rep orting low amplitude variability of certain ob jects crit
ically check if the quality of their data is su cient to assure that their claims are not a
result of spurious e ects e g caused by the usage of a non optimal observing technique
Quantitative statements ab out data quality such as the rms scatter of comparison star
measurements are imp erative
Acknowledgements This research was partially supp orted by the Austrian Fonds zur
F orderung der wissenschaftlichen Forschung under grant S
G HANDLER
Institut f ur Astronomie
T urkenschanzstra e
A Wien Austria
E mail HANDLER ASTRO AST UNIVIE AC AT
References
Breger M Handler G Baltic Astronomy
Clementini G PASP
Crawford D L AJ
Eggen O J MNRAS
Handler G The Observatory submitted
Handler G Breger M Sullivan D J et al A A submitted
Houk N Michigan Sp ectral Catalogue vol Department of Astronomy Univer
sity of Michigan Ann Arb or
Lee S W A AS
Yao B A Tong J H IBVS No YT
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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May
HU ISSN
X PERSEI
The Be X ray binary X Persei is the optical counterpart of X ray pulsar U
Possible orbital p erio d of the system is the day p erio dicity detected in the radial
velocities of the Balmer lines Hutchings in spite of existence of some doubts
Penrod Vogt The star is a known optical variable on time scales from minutes
to years The most comprehensive optical light curve over the past decades is presented
by Ro che et al
X Per has b een observed with cm telescop e and photon counting photometer of the
National Astronomical Observatory Rozhen HR V B V U B
served as the comparison star The APR software Kirov et al was used during
the data reduction
Our data are summarized in Table Figure presents the V band light curve over
the p erio d Our observations showed the optical low state that b egan in the
mid nished in the spring of Since this time the star has b een in optical high
state A clear similarity b etween the light maximum in and that in
is visible The displacement is ab out days i e times larger than the supp osed
orbital p erio d
The last observations indicate that the optical high state is almost over and X Per is
going to a new low state now May b e the star will lose its circumstellar disk again as it
was observed in Norton et al Ro che et al
Figure V band light curve of X Per Circles indicate our data The light curve b efore
JD is taken from Ro che et al
Table
JD V B V U B JD V B V U B
We gratefully acknowledge Dr N A Tomov for help in observations This work was
partly supp orted by NSF F
R K ZAMANOV
V I ZAMANOVA
NAO Rozhen POB
Planetarium POB
Smoljan Bulgaria
Smoljan Bulgaria
References
Hutchings J B MNRAS
Kirov N Antov A Genkov V Compt Rend Acad Bulg Sci No
Northon A J Co e M J Estela A et al MNRAS
Penrod G Vogt S ApJ
Ro che P Co e M J Fabregat J McHardy I M Norton A J Percy J R Reglero
V Reynolds A Unger S J A A
COMMISSIONS AND OF THE IAU
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May
HU ISSN
PHOTOELECTRIC OBSERVATIONS OF THE
ECLIPSING VARIABLE ER VULPECULAE
The eclipsing binary system ER Vul with the p erio d of days Northcott
and Bakos was observed during four nights July August with the
centimeter Cassegrain telescop e of Birouni Observatory Iran Shiraz latitude N
longitude E using a photo electric photometer equipp ed with an unrefrigerated
RCA photomultiplier tub e The observations were made through UBV lters which
are approximately in the standard system The probable errors of a single observation
were estimated to b e ab out in the three colours i e corresp onding to a measure of
the observational scatter at a particular phase The variable was observed di erentially
with resp ect to the comparison star HD The star HD was observed as
check star
Figures and show the UBV light curves for ER Vul resp ectively
The following light elements given by Ibanoglu et al were used in computing
the phases of the individual observations
d
Min I J D Hel : E
Table indicates the photo electric minimum times of ER Vul in the three di erent
lters
Table
J D Hel Filter Min
U II
B II
V II
U I
B I
V I
Table
Date Phase
July
July
July
August
Figure Figure
Figure
Our observations indicate the existence of asymmetry esp ecially in the b eginning of the
ascending part of the secondary minimum These phenomena can b e explained as a result
of the presence of a gaseous stream owing from the secondary to the primary comp onent
starting o roughly in the inner Lagrangian p oint and falling b ehind the primary as that
star moves round on its orbit Struve Also we see in our observations a shift for
primary and secondary minima from phases zero and
Table lists the dates of observations and phases covered The data has b een folded
so that b oth primary and secondary minima are clearly visible These observations do
indicate proximity e ects wave like distortions mutual eclipses and short term light uc
tuations see Northcott and Bakos
F ZEINALI
M T EDALATI
Physics Dept
School of Sciences
University of Ferdowsi
Mashad Iran
M T MIRTORABI
Birouni Observatory
University of Shiraz
Shiraz Iran
References
Ibanoglu C Akan M C Evren S and Tunca Z Inf Bul l Var Stars No
Northcott R J and Bakos G A Astronomical J
Struve O Astrophys J
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HU ISSN
CONFIRMATION OF VARIABILITY IN THE BOOTIS STARS
HD AND HD
For the Bo otis star HD two nights of di erential photometry were obtained
in the Str omgren photometric system The observations were done by E Paunzen with
the ESO cm telescop e at La Silla during the nights of and July An
integration time of seconds was chosen HD m B V and HD
V
m F were used as comparison stars The second comparison star was detected
V
as a new Scuti star which will b e presented in a forthcoming IBVS note Paunzen et
al unpublished
The variability of HD has b een investigated by Weiss et al where a
semi amplitude of mag in Str omgren b with a p erio d of ab out hours had b een
derived This photometry was not di erential b ecause at that time we were mainly
interested in roAp type variability Hence we had to rely in our analysis on a constant sky
transparency Furthermore the data sets obtained during the three nights were rather
short on the order of hours each
As part of our survey of pulsation among Bo otis stars we decided to reobserve
HD in two colors with the classical technique using two comparison stars Fig
Our new observations con rm the semi amplitude of mag in Str omgren b and
of in Str omgren v However the maximum amplitude in the frequency sp ectrum
is found at a shorter p erio d of ab out hours c d Fig This di erence may b e
caused by the fact that our earlier data sets have an extremely p o or duty cycle as well as
a short time base which did not allow us to resolve multiperio dicity and hence may have
led us to a di erent p erio d HD obviously pulsates in more than one frequency
b ecause amplitude mo dulation is evident already in our rather limited data set
The p erio ds of pulsating Bo otis stars usually are in the range of to hours
These values satisfy the PLC relation of Stellingwerf for early A type stars at the
ZAMS E ective temp erature and gravity of HD indeed are typical for an early
A type star But this Bo otis star pulsates with a p erio d which is to o long for a star at
the ZAMS This evidence may indicate that HD is evolved An extensive observing
campaign is required to investigate the evolutionary status of this star
Two additional nights of di erential photometry in the Str omgrensystem were obtained
by the same observer for the Bo otis star HD with the ESO cm telescop e
and July The integration time was seconds HD m F V
V
and HD m F V were used as comparison stars Fig
V
HD was previously observed in Paunzen and Weiss and found to
b e variable The amplitude was much smaller mmag than in the case of HD
and in addition the photometric quality of the nights was not excellent To corrob orate
the variability of HD we reobserved this star in 20 mmag (b)
0.50 0.55 0.60 0.65 0.70
JD 2.449.559 +
Figure Light curves for Str omgren b of HD top and HD b ottom for
the night of July
0.035
0.030
0.025
0.020
0.015
0.010
0.005 semi-amplitude in mag (b)
0.000 0 20 40 60 80 100
frequency (1/d)
Figure Amplitude sp ectrum of the di erential data HD HD for
b oth nights and for Str omgren b 20 mmag (b)
0.50 0.55 0.60 0.65
JD 2.449.558 +
Figure Light curves for Str omgren b of HD top HD center and
HD b ottom for the night of July
0.0035
0.0030
0.0025
0.0020
0.0015
0.0010
0.0005 semi-amplitude in mag (b) 0.0000
0 20 40 60 80 100
frequency (1/d)
Figure Amplitude sp ectrum of the di erential data HD HD for
b oth nights and for Str omgren b
Our new observations result in a frequency of ab out c d P minutes for b
and a semi amplitude of slightly more than mmag for b and v which is less than
what we found in The derived p erio d happ ens to b e ab out twice the p erio d found
in P min which again may b e caused by inadequate data sets aggravated by
multiperio dicity Presently we can only state that there is no doubt ab out the photometric
variability of HD A full analysis of this variable star can only b e based on improved
data preferably obtained within a multi site observing campaign
Acknowledgement This research was done within the working group Asteroseismology
AMS and was supp orted by the Ho chschuljubil aumsstiftung der Stadt Wien and the
International O ce of the University of Vienna
E PAUNZEN
U HEITER
W W WEISS
Institut f ur Astronomie
T urkenschanzstr
A Wien Austria
E mail PAUNZEN ASTRO AST UNIVIE AC AT
References
Paunzen E Weiss W W IBVS No
Stellingwerf R F ApJ
Weiss W W Paunzen E Kuschnig R Schneider H A A
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THE ACTIVE STAR RE
The sky was surveyed in the extreme ultraviolet by the satellites ROSAT Pounds et
al and EUVE McDonald et al and from the catalogues of these sources I
have b een lo oking for brightness variations in the F G and K sp ectral type stars This
is a rep ort ab out one of these stars namely RE BD
The automated m telescop e R lter and CCD camera of the Climenhaga Ob
servatory of the University of Victoria was used to make these photometric observations
Robb et al
The frames had the bias subtracted and were at elded in the usual manner using
IRAF The magnitudes were found from ap erture photometry using the PHOT package of
DAOPHOT Stetson The co ordinates of each star for photometry were found from
insp ection of a few frames taken at the b eginning middle and end of the night These
p ositions were used as initial p ositions for the Gaussian centering option which precisely
centered the arc second ap erture on each star for each frame
The mean and standard deviation of the comparison BD minus check star
R magnitude di erences are : : ensuring the constancy of b oth stars at this
level Due to the small eld of view rst order extinction e ects were negligible and
no corrections have b een made for them No corrections have b een made for the colour
di erence b etween the stars to transform it to a standard system
A sp ectrum of RE was obtained using the Dominion Astrophysical Observa
tory s m telescop e and B sp ectrograph on the January UT with a dis
p ersion of Angstroms p er pixel It is shown in Figure with a sp ectrum of HR a
well known RS CVn star of sp ectral type K V and a sp ectrum of Beta Cancri classi ed
as K I I I Yamashita et al Pounds et al rep ort a sp ectral type of Ge
RE has obvious emission in the Ca H and K lines indicating an active chromo
sphere This emission would tend to make one cautious ab out using the hydrogen lines to
make a classi cation since such an active star often has some hydrogen emission as well
Insp ection of the G Band and the Fe I and Cr I lines lead me to classify the
star as a K Ve
Photometric observations of RE were b egun on Julian Date and are
plotted in Figure It is obvious that there was a large brightening of the star at
hours UT This star was monitored on nights and at no time was a similar brightening
observed The cause of the brightening then must b e a large are UV Ceti type are
stars have a sp ectral type of late K or M and ares generally of a few minutes duration
but small amplitudes in the red region of the sp ectrum
Very energetic ares have b een seen on the close binary star V Tau HR by
Zhang et al rep orting an amplitude of in V and a duration of hours and
by Henry and Hall rep orting an amplitude of in V and a duration of or
RE0041
HR1099
K4III
3900 4000 4100 4200 4300 4400
Wavelength in Angstroms
Figure Sp ectra of RE HR and Beta Cancri
-0.60
-0.50
-0.40 Delta R Mag
-0.30
-0.20
-0.10 1.0 3.0 5.0 7.0 9.0 11.0
Hours Universal Time
Figure Di erential R magnitude as a function of Universal Time for RE on
Nov
0.0020
0.0015
0.0010 Chi Square
0.0005
0.0000 0.0 1.0 2.0 3.0
Inverse Period
Figure Periodogram of the August data
-0.25
-0.20
-0.15
-0.10 Delta R Magnitude
-0.05
0.00 0.0 0.2 0.4 0.6 0.8 1.0
Phase
Figure Di erential R magnitude phased on a p erio d of days for August
hours An even larger are may have b een the one seen on FK Comae G I I I rep orted by
Morris and Milone The R band amplitude of the are on RE was
magnitudes and its duration was ab out hours Thus the are observed on RE
was exceptionally large but not unique
During the winter of variations of brightness from night to night were obvious
and the few long nights showed that the p erio d of the variation must b e more than a few
hours However p erio dograms of this data were inadequate to reveal a b elievable p erio d
Observations were made on eight more nights in the summer of and a sine curve t
to this data reveals a minimum chi squared at a p erio d of : : days as seen in Figure
A plot of the di erential R magnitudes for the summer data phased at this p erio d
is shown in Figure In spite of six of the nights b eing observed in one week there is some
variation in the mean brightness from night to night The winter data phased on this
p erio d show a similar light curve with a slightly di erent shap e Three more nights were
observed in September and showed no detectable variation and a mean di erence in
R magnitude of : So the variations are probably caused by starsp ots and di erential
rotation or sp ot evolution cause the brightness variations to change on a monthly time
scale Since the brightness variations are not strictly p erio dic the p erio d found is only
approximately that of the rotation of the star
RE is a rapidly rotating K V star with active regions on its surface causing
brightness variations EUV emission Ca H and K emission and ares The author wishes
to thank David Balam for assistance in obtaining the sp ectra at the DAO
R M ROBB
Visiting Astronomer at the
Dominion Astrophysical Observatory
and the
Climenhaga Observatory
of the Dept of Physics and Astronomy
University of Victoria
Victoria BC CANADA V W P
Internet robb uvphys phys uvic ca
References
Henry G W and Hall D S ApJ L
McDonald K Craig N Sirk M M Drake J J Fruscione A Vallerga J V and
Malina R F AJ
Morris S L and Milone E F PASP
Pounds K A et al MNRAS
Robb R M and Honkanen N N in A S P Conf Ser Automated Telescopes
for Photometry and Imaging ed Adelman Dukes and Adelman
Stetson P B PASP
Yamashita Y Nariai K and Norimoto Y An Atlas of Representative Stellar Sp ectra
A Halsted Press Bo ok John Wiley Sons New York and Toronto
Zhang R Zhai D Zhang X Zhang J Li Q IBVS No
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HS VIRGINIS A DWARF NOVA WITH
DAY OUTBURST CYCLE LENGTH
HS Vir was discovered as an ultraviolet excess ob ject PG and was subse
quently con rmed by sp ectroscopy to b e a cataclysmic variable by Green et al
They rep orted two magnitude variability but its nature remained little revealed
Some authors have classi ed this ob ject as a nova like star others as a dwarf nova with
a small amplitude
Photographic photometry was undertaken by Osminkin who showed existence
of relatively frequent short faint outbursts and presence of a bright mag outburst
Unfortunately Osminkin s observations were so sparsely done that the materials were not
enough to determine the outburst parameters or the dwarf nova subtype Howell et
al tried to get the orbital p erio d of this system by photometry made during
quiescence but the result remained inconclusive
Another imp ortant observation was carried out by Ringwald He obtained
a number of radial velocity mesurements and derived the b est estimate of the orbital
p erio d of day with p ossible aliasing problems which is just b elow the lower edge
of the p erio d gap This suggests that HS Vir may b e a candidate of SU UMa type dwarf
nova for a review see Warner One problem of this suggestion is that HS Vir
has much smaller outburst amplitude mostly mag which makes a clear contrast to
usual SU UMa type dwarf novae However recent discovery of a new subgroup of low
outburst amplitude SU UMa type dwarf novae named ER UMa stars or RZ LMi stars
Kato and Kunjaya Nogami et al Rob ertson et al Misselt and Shafter
hereafter ER UMa stars has called our attention to HS Vir with a similar outburst
amplitude
Observations were carried out using a CCD camera Thomson TH
pixels attached to the Cassegrain fo cus of the cm re ector fo cal length m at
Ouda Station Kyoto University Ohtani et al To reduce the readout noise and
dead time an on chip summation of pixels to one pixel was adopted An interference
lter was used which had b een designed to repro duce the Johnson V band The exp osure
time was b etween and s The frames were rst corrected for standard de biasing
and at elding and were then pro cessed by a micro computer based automatic ap erture
photometry package developed by one of the authors T K The di erential magnitudes
h m s 0 00
of the variable were determined using a lo cal standard star C : :
J V The p osition and magnitude were taken from the Guide Star Catalog
The constancy of this comparison was checked against several stars in the same eld C
and C see Figure
The resulting general light curve is given in Figure The light curve rst clearly
established the dwarf nova nature of HS Vir with a very stable outburst cycle length of
0
N
50 C1
100
E C3 C2
pixel 150
HS
200
250
0 50 100 150
pixel
Figure Field map of HS Vir The eld of view is ab out arcmin The variable
HS comparison C and check stars C and C are marked The C and C were
measured to b e fainter than C by and mag resp ectively
1
HS Vir 2
3 Relative Magnitude 4
5
30 40 50 60 70 80 90 100 110 120
HJD-2449700
Figure V band light curve of HS Vir The zero p oint of the relative magnitudes
corresp onds to V Regular short outbursts spaced by days are evident
days The observed amplitudes of outbursts were mag which are clearly smaller
than those of usual dwarf novae Other imp ortant p oints are the shortness of outbursts
one or two days and the rapid decline up to mag d from the outburst p eak The
shortness and the rapid decay of outbursts are very characteristic of normal outbursts of
SU UMa type dwarf novae The shortest known recurrence time of normal outbursts in
SU UMa stars had b een days in YZ Cnc b efore the discovery of ER UMa stars This
value of HS Vir closely matches that of YZ Cnc except outburst amplitudes which are
more similar to those of ER UMa stars Although we have not yet detected sup eroutburst
nor sup erhumps in this system a search for these phenomena would surely bring the long
confusing history of HS Vir to an end and would prove the p osition of HS Vir among a
group of low outburst amplitude SU UMa type dwarf novae i e YZ Cnc ER UMa stars
and V Cyg Harvey et al
A record of the brightest outburst on JD by Osminkin although
severely undersampled shows that this outburst lasted more than three days and this
outburst may b e identi ed as a sup eroutburst Con rmation of sup eroutbursts and su
p erhumps and determination of sup ercycle recurrence time of sup eroutbursts will b e a
next imp ortant step toward full understanding of this rather p eculiar dwarf nova
Part of this work is supp orted by a Research Fellowship of the Japan So ciety for the
Promotion of Science for Young Scientists T K
Taichi KATO
Daisaku NOGAMI
Seiji MASUDA
Ryuko HIRATA
Dept of Astron Faculty of Sci
Kyoto University
Sakyo ku Kyoto Japan
References
Green R F Ferguson D H Lib ert J Schmidt M PASP
Green R F Schmidt M Lieb ert J ApJS
Harvey D Skillman D R Patterson J Ringwald F A PASP in press
Howell S B Szkody P Kreidl T J Mason K O Puchnarewicz E M PASP
Kato T Kunjaya C PASJ
Misselt K A Shafter A W AJ
Nogami D Kato T Masuda S Hirata R IBVS No
Ohtani H Uesugi A Tomita Y Yoshida M Kosugi G Noumaru J Araya S
Ohta K et al Memoirs of the Faculty of Science Kyoto University Series
A of Physics Astrophysics Geophysics and Chemistry
Osminkin E Yu Perem Zvezdy
Ringwald F A Ph D thesis Dartmouth College
Rob ertson J W Honeycutt R K Turner G W PASP in press
Warner B Interacting Binaries ed P P Eggelton J E Pringle D Reidel Pub lishing Company Dordrecht p
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
TIMES OF MINIMA OF EIGHT ECLIPSING BINARIES
We rep ort times of minima of eccentric eclipsing binaries derived from photometric
observations made at Ege University Observatory in Turkey and at Cerro Tololo Inter
american Observatory CTIO in Johnson B and V lters and at the High Altitude
Maidanak Observatory in Uzb ekistan in Johnson U B V R lters Helio centric times of
minimum were estimated for each lter by using the metho d of Kwee and Van Woerden
as adapted to a Macintosh computer The adopted time of minimum was then the
average over all lters In all cases the times of minimum in di erent lters was concor
dant Uncertainties in the times of minima were estimated from the values of standard
error computed by the metho d and from the di erences in times derived from the various
lters used Primary eclipses are designated as type eclipses and secondary eclipses as
type
We would like to acknowledge nancial supp ort of our work by the American Astro
nomical So ciety through the Edith J Woo dward Award and from the Margaret Cullinan
Wray Charitable Lead Annuity Trust
Mamnun ZAKIROV
Claud H SANDBERG LACY
G ARZUMANYANTS
Department of Physics
R ISHANKULOV
University of Arkansas
V KHARCHENKO
Fayetteville Arkansas
High Altitude Maidanak Observatory
USA
Astronomical Institute
Cafer IBANOGLU
Tashkent
Z TUNCA
Uzb ekistan
S EVREN
C AKAN
V KESKIN
Ege University
Bornova Izmir
Turkey
Reference
Kwee K K and van Woerden H B A N
Star JD of Min Type Observatory
IT Cas Maidanak
Maidanak
Maidanak
Maidanak
PV Cas Ege
Ege
Ege
Ege
Ege
Ege
Ege
Ege
Ege
Maidanak
Ege
Ege
Maidanak
EK Cep Ege
Ege
Ege
Ege
Ege
V Cyg Maidanak
V Lac Ege
Ege
Ege
FS Mon CTIO
FT Ori Ege
Ege
CTIO
CTIO
CTIO
GG Ori Maidanak
Maidanak
Maidanak
Maidanak
CTIO
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
A LIST OF VARIABLE STARS SIMILAR TO Dor
In this note we compile data on stars that app ear to constitute a new class of variable
stars These stars typically have sp ectral types near F and luminosity classes of V or
IV V They are variable up to mag in V on a time scale of to days an order of
magnitude longer than the fundamental radial pulsation p erio d for stars of this density
Some exhibit two or more frequencies The evidence is that these stars are variable owing
to non radial g mo de pulsations Given that Dor was the rst one found to b e variable
Cousins Warren it has b een suggested that they b e known as Doradus
stars Our list is a consequence of the rapidly growing scienti c interest in these stars
For instance multi longitude campaigns are planned for four of the stars during
these are necessary to avoid aliasing of the frequencies of variation for stars with day
p erio ds
In Tables and resp ectively we give various data on the b ona de members of
the group on other candidates and on one star formerly regarded as b eing of the Dor
type The co ordinates are equinox The photometric p erio ds are given in days
1
The pro jected rotational velocities v sin i are in km s Table is only for stars with
a considerable amount of available data Table contains all ob jects we found in the
literature which were rep orted to b e related with the Dor phenomenon In the tables
we provide Str omgren photometry from Hauck Mermilliod supplemented by
new observations of Handler In the references we include only published pap ers
We do note however that Zerbi private communication informs us there is a pap er in
preparation on NGC which provides evidence for additional four Dor candidates
in that cluster
Table Bona Fide Members
Star HD V b y m c
1 1
RA DEC Sp Period s v sin i Remarks References
F
Dor
F V
Aur
F V
Pup B
A V or
F IV V
F
Table Other Candidates
Star HD V b y m c
1 1
RA DEC Sp Period s v sin i Remarks References
A V
NGC C
NGC C
NGC C
NGC C
1
Hya A
F V days
F V
Vir
F V
A IV V
F V
BS
A V
Table Star formerly on the list
Star HD V b y m c
1 1
RA DEC Sp Period s v sin i Remarks References
F V
References to Tables
Breger M ApJ
Cousins A W J The Observatory
Balona L A et al MNRAS
Krisciunas K et al MNRAS
Antonello E Mantegazza L A A
Lamp ens P A A
Matthews J M A A
Mantegazza L Poretti E Antonello E IBVS No
Abt H A Bollinger G Burke E W Jr ApJ
Rucinski S M PASP
Mantegazza L Poretti E IBVS No
Mantegazza L et al ASP Conf Ser
Kazovarets E V Samus N N IBVS No
Mantegazza L Poretti E Zerbi F M MNRAS
Mantegazza L Poretti E A A See also Delta Scuti Star Newsletter
Vienna No
Krisciunas K et al MNRAS
Ro driguez E Zerbi F M IBVS No
Lo ckwoo d G W Ski B A Thompson D T IAU Collo q Stellar
Photometry Current Techniques and Future Developments C J Butler
I Elliott eds p
Handler G Delta Scuti Star Newsletter Vienna No
Vaz L P R Andersen J A A
Balona L A Krisciunas K Cousins A W J MNRAS
Hall D S Rob otic Telescopes Current Capabilities Present Developments
and Future Prosp ects for Automated Astronomy G W Henry J A Eaton eds
ASP Conf Series No p
Ho eit D JAAVSO
Remarks to Tables
Aur was designated V Aur in the latest name list of variable stars Ref ab ove
Cluster membership doubtful Ref ab ove Str omgren indices suggest high metallicity thus the absolute
magnitude of the star in Figure could b e to o low
Period uncertain due to aliasing
The magnitudes and colors given are for the slightly brighter of the two nearly identical comp onents
Note correct HD number
Shown to b e an ellipsoi dal binary Ref ab ove
Figure Color magnitude diagram of the stars similar to Dor Circles stars from
Table Triangles NGC stars Dots other candidates from Table The Zero
Age Main Sequence is adopted from Crawford while the b orders of the instability strip are taken from Breger
In Figure we give a color magnitude diagram of the b ona de members and the
other candidates For eld stars and doubtful members of clusters we calculated the
unreddened colors and absolute magnitudes from the Str omgrenphotometry by applying
the calibrations of Crawford
The authors would appreciate receiving from other observers further data and news of
new candidates since this list will b e continuously up dated
Some information in the table was obtained from the simbad data retrieval system a
data base of the Astronomical Data Centre Strasb ourg France
Acknowledgements L Mantegazza kindly supplied a program for calculating dered
dened colors and absolute magnitudes from uvby photometry
?
K KRISCIUNAS
??
G HANDLER
?
Joint Astronomy Centre N A oh ok uPlace University Park Hilo Hawaii
USA e mail kevin jach hawaii edu
??
Institut f ur Astronomie T urkenschanzstra e A Wien Austria
e mail handler astro ast univie ac at
References
Breger M PASP
Cousins A W J Warren P R MNASSA
Crawford D L AJ
Crawford D L AJ
Handler G The Observatory submitted
Hauck B Mermilliod M A AS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
PERIODS AND TYPES FOR SIX RED VARIABLES
Kaiser rep orted the photographic discovery of several new variable stars
and the rediscovery of several variables listed in the New Catalogue of Susp ected Variable
Stars Kholop ov et al I have examined these stars on Harvard patrol plates of
the Damon blue series I Ia O from This rep ort presents the results for six
DHK variables of late sp ectral type Except when noted magnitudes of comparison stars
were estimated with an image scale calibrated to photo electric B magnitudes in nearby
elds of the Guide Star Photometric Catalogue Lasker Sturch et al Equatorial
co ordinates and alternate identi cation in various catalogues can b e found in the st and
nd Name Lists of Variable Stars as cited
DHK TT Sextantis
Sp ectral type M Designated TT Sex in the st Name List Kazarovets et al
Observed on plates using a comparison star sequence extended from the two compari
son stars for BV RU Sex cited by Strohmeier et al Observed range
ptg The light curve Figure gives a sup er cial impression of semiregular variations
but detailed plots of each season s data show that no two cycles are similar DFT analysis
found only a weak frequency p eak near days but this p erio d is expressed by only one
cycle on the light curve centered at JD Altogether these observations suggest
that variations are of the slow irregular type
DHK V Tauri
Sp ectral type C I I Designated V Tau Kazarovets et al Observed on
plates range ptg The discovery rep ort Kaiser gave this variable
an uncertain assigment to the slow irregular class Lb DFT analysis found a strong
frequency p eak at P days and a second mo derately strong p eak at P days
Therefore this star app ears more likely to b e SR type with long and p erhaps multiple
p erio ds
DHK V Cassiop eiae
Sp ectral type M First noted by Espin Recently designated V Cas in the
nd Name List Kazarovets and Samus Observed on plates range
ptg The light curve Figure shows distinct semiregular variations with the amplitude
of each cycle ranging from magnitude DFT analysis indicates a p erio d of
days which sup ersedes the estimate of days in the discovery rep ort
Figure
DHK BP Canum Venaticorum
Sp ectral type K Observed on plates Recently designated BP CVn Kazarovets
and Samus Variability was rst rep orted by Weber who found a range
of ptg I adopted his comparison sequence but found it necessary to add two
fainter stars to accommo date my observed range of ptg The light curve Fig
ure shows semiregular variations generally characterized by steep minima and broad
maxima DFT analysis found a strong frequency p eak at P days which sup ersedes
the preliminary estimate of days in the discovery rep ort
DHK V Persei
Sp ectral type M Recently designated V Per Kazarovets and Samus Ob
served on Damon plates using comparison star magnitudes interpolated from the HU
Per sequence of Meshkova less than degree east of this new variable Observed
range ptg DFT analysis found a strong frequency p eak at P days which
is expressed by two prominent cycles on the light curve Figure However additional
observations from RH series plates show only a weak frequency p eak at
days and no sign of a p erio d near days This star is probably a slow irregu
lar variable with characteristic cycles of days and minor variations of shorter
durations
DHK LM Pegasi
Sp ectral type M Recently designated LM Peg Kazarovets and Samus Ob
served on plates range ptg DFT p erio d search found a weak frequency
p eak equivalent to a p erio d of days which sup ersedes the estimate of days in the
discovery rep ort A light curve is not included here a forthcoming rep ort will present
photo electric photometry that supp orts the new p erio d This star app ears to b e a typical
small amplitude short p erio d red semiregular variable
Some of the information in this rep ort was obtained from SIMBAD database of Stras
b ourg France Astronomical Data Center I wish to thank Dr Martha Hazen for the
opp ortunity to use the Harvard College Observatory plate collection for this pro ject
David B WILLIAMS
A Racquetball Way
Indianap olis IN USA
References
Espin T E Astron Nach
Kaiser D H Inform Bul l Var Stars No
Kaiser D H Inform Bul l Var Stars No
Kazarovets E V and Samus N N Inform Bul l Var Stars No
Kazarovets E V Samus N N and Goranskij V P Inform Bul l Var Stars
No
Kholop ov P N editor et al New Catalogue of Susp ected Variable Stars Moscow
Lasker B Sturch C et al Astrophys Journ Suppl
Meshkova T S Perem Zvezdy
Strohmeier W Knigge R and Ott H Inform Bul l Var Stars No
Weber R Inform Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
BH Cas IS AN ECLIPSING BINARY
The variability of BH Cas was discovered by Beljawsky and con rmed by
Kukarkin who classi ed it as p ossibly W UMa type with p erio d days Ah
nert and Ho meister found no star in the region of BH Cas with the prop osed
variation Metcalfe published observations supp orting the variability of BH Cas
In Figure observations of BH Cas obtained in the V band on the nights of Octo
b er squares and February triangles are shown The comparison star was
GSC with a measured apparent visual magnitude of
The light curve con rms that BH Cas is an eclipsing binary of W UMa type counter
to the conclusion of Ahnert and Ho meister The p erio d is P days and the HJD
ep o chs of primary and secondary minimum are T and T
resp ectively Observations in the B and R bands indicate that B V and
V R
1.1
1.0
0.9
0.8
0.7
0.6 DIFFERENTIAL MAGNITUDE 0.5
0.4 -0.25 0.00 0.25 0.50 0.75
ORBITAL PHASE Figure
Future e orts at Steward Observatory will b e concentrated on improving the V band
light curve and determining a more precise p erio d Collab oration is esp ecially needed
for reconstruction of the B and R band light curves Observers at greatly di erent
h m
longitudes than Steward L ' would b e most welcome For nder charts or
w
additional information please contact the undersigned
T S METCALFE
Steward Observatory
University of Arizona
Tucson Arizona USA
tmetcalf astro as arizona edu
References
Ahnert P and Ho meister C KVBB
Beljawsky S AN
Kukarkin B W NNVS
Metcalfe T S IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
NSV Bo o BV RR ab VARIABLE
Geier Kipp enhahn and Strohmeier discovered the variability of the star NSV
Bo o BV They rep orted brightness variations on a short time scale Filatov
gave photographic observations of the star stating ep o chs of maximum light Finally
G otz and Wenzel communicated the sp ectral type of the variable F They also
remarked that they found a pair of stars of similar brightness and sp ectral type at the
given lo cation According to the bibliographical le on variable stars kept at Sonneb erg
Observatory Germany no other source of information on NSV Bo o is known
One of us LM observed NSV Bo o photographically in with the cm
Ritchey Chr etienre ector of the public observatory Sternwarte Eschenberg in Win
terthur Switzerland His observations were secured on nights over a timespan
of days These observations have never b een published They showed convincingly
that NSV Bo o BV is an RRab type variable But unfortunately the p erio d of
variation could not b e determined b ecause only one rather uncertain time of maximum
light JD max hel was observed
In the course of an observational stay at the Rosemary Hill Observatory of the Univer
sity of Florida RD reobserved NSV Bo o photo electrically in The details of the
instrumental setup were rep orted elsewhere Diethelm A total of observations
in V and measurements in B were secured b etween JD and JD As
rep orted by G otz and Wenzel NSV Bo o is the following of a close pair of
stars We used the leading member of the pair as the comparison star We found this
star to b e constant to within the accuracy of our photometry by o ccasional checks using
the standard star HR From this di erential photometry B and V
can b e deduced for the primary comparison star
The short time base of only days prevents the determination of accurate elements of
variation for the star from the photo electric data The p erio d value of P days
yields the smo othest light curve in V while the photographic data are b est represented by
a p erio d of days We have assumed that pulsations have taken place b etween
the photographic maximum determined by LM and the photo electric maximum observed
by RD JD for the computation of the provisional elements
JD hel max E
Figures and show the photo electric V and B V light curve folded with the elements
given in
The photo electric data yield the following basic parameters describing the light curve
of NSV Bo o
p
V V B B M m :
Figure Photo electric V light curve of NSV Bo o
Figure Photo electric B V colour curve of NSV Bo o
Acknowledgements RD would like to thank the sta of the Department of Astronomy
of the University of Florida for the generous allo cation of observing time and the contin
uous supp ort during his stay at the Rosemary Hill Observatory This investigation was
supp orted in part by the Emilia Guggenheim Schnurr Foundation
L MOSER
R DIETHELM
Sto ckhornstrasse
BBSAG
CH Konol ngen
Rennweg
Switzerland
CH Ro dersdorf
Switzerland
e mail diethelm astro unibas ch
References
Diethelm R IBVS No
Filatov G S Sov Astr Circular No
Geier E Kipp enhahn R Strohmeier W KVB No
G otz W Wenzel W MVS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
ORBITAL PARAMETERS OF SIX
SPECTROSCOPIC BINARY CEPHEIDS
Our observations of Cepheid radial velocities using a CORAVEL type photo electric
correlational sp ectrometer Tokovinin started in The results for
were presented in the form of a catalog of Cepheid radial velocities Gorynya et al
a This catalog contains ab out observations of nearly galactic Cepheids Our
observations were continued and in we obtained more than radial velocity
measurements for Cepheids Thus our data base of original accurate typical r m s
error ab out km s radial velocity measurements contains more than observations
for Cepheids We have also compiled a data base of all published radial velocity
measurements for Cepheids for Cepheids of our programme this data base quotes a little
more than observations Our programme aims to gather go o d coverage of radial
velocity curves optimally for each year of observations of a star As the result these
data are well suited for the search and study of sp ectroscopic binary Cepheids It is well
known that sp ectroscopic binarity is a common phenomenon among classical Cepheids
Szabados
We were able to con rm a number of earlier known sp ectroscopic binaries Moreover
we have discovered several new ones MW Cyg Gorynya et al b VZ Cyg Samus
et al BY Cas Gorynya et al
The present pap er is devoted to new determinations of orbital elements for six Cepheids
with long series of radial velocity measurements available We used our measurements
along with published data extracted from our data base
In calculations of orbital elements the pulsational curve was approximated by trigono
metrical series of the order from to with light elements taken from our data base
The search for orbital p erio ds used our standard software for analyzing p erio dicities of
variable stars The quality of approximation may b e seen in the orbital and pulsational
radial velocity curves presented in Figures a b We ascrib ed to each data p oint b oth in
the orbital and the pulsational curves half of individual residual of radial velocity
Table presents the results of our computation of orbital elements N and n are
resp ectively the total number of velocity observations used and the number of our original
velocity measurements for each star We estimate the error of orbital p erio ds as
days that of p ericenter ep o chs as days that of orbital eccentricities as that
of V as km s
Table
New Orbital Elements for Cepheids
FF Aql BY Cas VZ Cyg MW Cyg S Sge V Sgr
T JD
0
P d
or b
e
deg
V km s
K km s
f M
N
n
Figure a FF Aql VZ Cyg MW Cyg decomp osition of the radial velocity data into
orbital left and pulsational right comp onents
Figure b BY Cas S Sge V Sgr decomp osition of the radial velocity data into
orbital left and pulsational right comp onents
This study was partially supp orted by ISF grant NDD RFFR grants
and Astronomy Program of Russian Federation grants
N A GORYNYA
N N SAMUS
Institute of Astronomy
of Russian Academy of Sciences
Pyatnitskaya Str
Moscow Russia
L N BERDNIKOV
A S RASTORGOUEV
M E SACHKOV
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
References
Gorynya N A Irsmambetova T R Rastorgouev A S and Samus N N a Sov
Astron Lett No
Gorynya N A Samus N N Irsmambetova T R Kulagin Yu V Rastorgouev A S
Smekhov M G and Tokovinin A A b Inf Bul l Var Stars No
Gorynya N A Samus N N and Rastorgouev A S Inf Bul l Var Stars No
Samus N N Gorynya N A Kulagin Yu V and Rastorgouev A S Inf Bul l
Var Stars No
Szabados L Paper presented at the IAU Collo quium No
Tokovinin A A Soviet Astronomy
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
PHOTOELECTRIC OBSERVATIONS
OF THE T Tau TYPE VARIABLE BZ Sgr
BZ Sgr was included in our program of photo electric observations of Cepheids b ecause
it was listed in GCVS IV as a p ossible type I I Cepheid Recently it was found that this
star was a T Tau type variable Gregorio Hetem et al
Table
JD hel V U B B V V R R I
c c
Our photo electric UBV RI measurements were carried out at CTIO Las Campanas
c
and Mt Maidanak observatories from June to March Everywhere cm
re ectors were used and observations were obtained These observations are listed in
Table The accuracy of the individual data is near mag in all lters
The research describ ed in this publication was made p ossible in part by grants No NDD
and No NDD from the International Science Foundation and Russian Government
as well as by grant No from the Russian Foundation of Basic Research to
LNB and OVV and by funds awarded through the Natural Sciences and Engineering
Research Council of Canada NSERC to DGT
L N BERDNIKOV
O V VOZIAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
D G TURNER
St Mary s University
Robie st
Halifax NS B H C Canada
Reference
Gregorio Hetem J Lepine J R D Quast G R Torres C A O and de la Reza R
Astron J