COMMISSIONS AND OF THE I A U
INFORMATION BULLETIN ON VARIABLE STARS
Nos
March November
EDITORS L SZABADOS K OLAH
TECHNICAL EDITOR A HOLL
TYPESETTING K ORI
ADMINISTRATION Zs KOVARI
EDITORIAL BOARD L A BALONA M BREGER E BUDDING M deGROOT
E GUINAN D S HALL P HARMANEC M JERZYKIEWICZ K C LEUNG
M RODONO N N SAMUS J SMAK C STERKEN
H BUDAPEST XI I Box HUNGARY
HU ISSN
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CONTENTS
E PAUNZEN G HANDLER Pulsation of HD and HD ::::
E PAUNZEN W W WEISS R KUSCHNIG Nonvariability among
Bo o Star I ESO and Data ::::::::::::::::::::::::::::::::::
P A HECKERT Photometry of SV Camelopardalis ::::::::::::::::
M WOLF L SAROUNOVA P MOLIK Period Changes in V
Ophiuchi ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::
R M ROBB M D GLADDERS Optical Observations of the Active
Star FF Cancri ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::
U BASTIAN E BORN F AGERER M DAHM V GROSSMANN
V MAKAROV Con rmation of the Classi cation of a New Tycho Variable
HD is a Day Cepheid :::::::::::::::::::::::::::::::::::::::::::
G OPRESCU A DUMITRESCU P ROVITHIS
H ROVITHIS LIVANIOU New Times of Minima of the Eclipsing Binaries
i Bo otis and VW Cephei :::::::::::::::::::::::::::::::::::::::::::::::
T BERTHOLD New Elements for the Eclipsing Binary ZZ Cnc :::::::::
P ROVITHIS H ROVITHIS LIVANIOU A KRANIDIOTIS Minimum
Times and Period Behaviour of the Neglected Eclipsing Binary WZ Cygni
R KUSCHNIG M GELBMANN E PAUNZEN W W WEISS
Nonvariability Among Bo otis Stars I I SAAO CTIO
and IAA Data ::::::::::::::::::::::::::::::::::::::::::::::::::: :
C STERKEN N VOGT R E MENNICKENT On the Peculiar Flickering
Activity of HR ::::::::::::::::::::::::::::::::::::::::::::::::::: :::
D D BALAM Optical Observation of SN C in MCG ::::::
L A BALONA L BREGMAN B A LETSAPA B T MAGORO
S E WALSH The Pulsation Frequencies of CMa :::::::::::::::::::::::
A V KUSAKIN D E MKRTICHIAN Multip erio dicity in Pulsating
Lambda Bo o Star Cyg HD V Cyg :::::::::::::::::::::::
A P ANTOV R KONSTANTINOVA ANTOVA E SEMKOV
N BORISSOV Tsv GEORGIEV V UMLENSKI New Deep Minimum of
the Cataclysmic Binary KR Aur in :::::::::::::::::::::::::::::
K N GRANKIN Rotation Periods for Four Low Mass Stars in the
Taurus Auriga Region with CaI I Emission ::::::::::::::::::::::::::::::::
F CAMPOS CUCARELLA J GUARRO FLO
J M GOMEZ FORRELLAD E GARCIA MELENDO Photometric
Observations of the New Bright Classical Cepheid SAO HD :
E PAUNZEN G HANDLER New Photometric Data for HD and
HD ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::
G A RICHTER J GREINER NSV and RX J :::::::
J VANDENBROERE New Information on V Cas Type and Period
R DEMARTINO D KOCYLA Ch PREDOM E WETHERBEE
Accurate Positions of Variable Stars Near the South Galactic Pole ::::::::
R DEMARTINO D KOCYLA Ch PREDOM E WETHERBEE
Accurate Positions of Susp ected Variable Stars Near the South Galactic
Pole ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::::
F CAMPOS CUCARELLA J NOMEN TORRES
J M GOMEZ FORRELLAD E GARCIA MELENDO NSV a Low
Amplitude RRab Star in Camelopardalis :::::::::::::::::::::::::::::::::
J VIDAL SAINZ J M GOMEZ FORRELLAD E GARCIA MELENDO
The New Overcontact System GSC in Andromeda and a Star
Showing an Optical Transient ::::::::::::::::::::::::::::::::::::::::::::
FU JIAN NING JIANG SHI YANG Has the Delta Scuti Star AD CMi
a Companion ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::
LIU QUINGYAO YANG YULAN GU SHENGHONG HANG ZHANKUI
AH Flare on UV Piscium ::::::::::::::::::::::::::::::::::::::::::::::
S OZDEMIR M TANRIVER UBV Photometry of V Per :::::::::::
M TSVETKOV E SEMKOV K TSVETKOVA V HAMBARYAN
Observations of the Flare Star V Cygni ::::::::::::::::::::::::::::::
L DAHLMARK New Variable Stars in Cygnus Lacerta and Andromeda
M BOS G HUDSON R HUDSON E BUDDING UBV Observations
of AB Dor Late ::::::::::::::::::::::::::::::::::::::::::::::::::: :
S L KIM S W LEE HD a New Eclipsing Binary in the Op en
Cluster M NGC ::::::::::::::::::::::::::::::::::::::::::::::::
F AGERER W KLEIKAMP W MOSCHNER E SPLITTGERBER
V Cassiop eiae is an RR Lyrae Type Variable ::::::::::::::::::::::::::
M WOLF L SAROUNOVA GSC a New W UMa Type
Eclipsing Binary in the Field of GG Ori ::::::::::::::::::::::::::::::::::
J WINTERBERG A BRUCH Light curves and Periods of the RR Lyrae
Stars SU Cha and SW Cha :::::::::::::::::::::::::::::::::::::::::::::::
C LLOYD K W WEST Observations of Low Amplitude Late Type
Variables ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::
F MONTAGNI M MAESANO R VIOTTI A ALTAMORE
M TOMOVA N TOMOV Photometry of the Active Phase
of AG Dra ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::
R DIETHELM GT Aquarii New Elements :::::::::::::::::::::::::::::
J GREINER J M ALCALA CI Aquilae :::::::::::::::::::::::::::::::
E H SEMKOV Photographic and CCD Photometry of V Cephei :::::
T HEGEDUS I B BIRO T BORKOVITS ZS PARAGI Photo electric
Minima of Eclipsing Binary Systems :::::::::::::::::::::::::::::::::::
N TOMOV M TOMOVA Photo electric UBV Observations of
EG Andromedae ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::
S V ANTIPIN New Variable Stars in the Herculis Field :::::::::::::::
S V ANTIPIN New Variable Stars in the Coronae Borealis Field ::::::
S V ANTIPIN New Variable Stars in the Ophiuchi Field :::::::::::::
S V ANTIPIN Nine New Variables in the Ophiuchi Field ::::::::::::
T KIPPER V G KLOCHKOVA The Sp ectrum of FG Sagittae in
C E LOPEZ H S LEPEZ Improved Positions of Variable Stars in Ara I
P MARTINEZ Discovery of min Oscillations in the Ap Sr EuCr Star
HD ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::
R KUSCHNIG M GELBMANN E PAUNZEN W W WEISS
Photometric Variability of the Bo otis Star HD ::::::::::::::::::::
Erratum ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::
M D GLADDERS R M ROBB Discovery of the New RR Lyrae Star
::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::: GSC
E PAUNZEN G HANDLER W W WEISS Nonvariability among
Bo otis Stars I I I CTIO and McDonald Data :::::::::::::
L KOHOUTEK HBV a New Variable Star in Hercules :::::::::::::
Ch WETTERER R GRASHUIS R KUNKLE K BOUDREAU CCD
Photometry of CN Tau V Lyr V Cyg and GS Lyr ::::::::::::::::
G V WILLIAMS Indenti cation of Dahlmark Variables :::::::::::::::::
K KRISCIUNAS K D LUEDEKE Photometry of Orionis Octob er
to April ::::::::::::::::::::::::::::::::::::::::::::::::::: :::
A GARRIGOS SANCHEZ NSV an RR Lyrae Type Star in
Ophiuchus ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::
N I DOROKHOV T N DOROKHOVA Great Optical Outburst of
A V Tauri ::::::::::::::::::::::::::::::::::::::::::::::::::
B PAULEY B CARRIGAN J FRENCH MI IN LOOI R G SAMEC
U B V Light Curves and Period Behaviour for the Solar Type Eclipsing
Binary V Aquilae ::::::::::::::::::::::::::::::::::::::::::::::::::: :
J D GRAY S WOISSOL R G SAMEC B V R I Light Curves
c c
of the Southern Very Short Period Eclipsing Binary V Centauri ::::::::
S V ANTIPIN Nine New Variables in the Herculis Field ::::::::::::::
S V ANTIPIN New Sup ernova on Moscow Plates ::::::::::::::::::
E F GUINAN J A MALEY J J MARSHALL Eccentric Eclipsing Binary
Stars as Test of General Relativity the Case of V Cygni :::::::::::::::
J F BURNS E F GUINAN J J MARSHALL New Apsidal Motion
Determination of the Eccentric Eclipsing Binary V Cygni :::::::::::::
J M GOMEZ FORRELLAD E GARCIA MELENDO NSV is an
Overcontact Eclipsing Binary Star ::::::::::::::::::::::::::::::::::::::::
J NOMEN TORRES E GARCIA MELENDO The New Overcontact
Eclipsing Binary Star NSV :::::::::::::::::::::::::::::::::::::::::
R HAEFNER A FIEDLER S RAU CCD Photometry of Eight
Susp ected Cataclysmic Variables :::::::::::::::::::::::::::::::::::::::::
D L DUPUY R H BLOOMER New Observations of Four Galactic
Cepheids ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::
M MIKOLAJEWSKI T V TOMOV D KOLEV L LEEDJARV
CH Cygni a Tenth Magnitude Star ::::::::::::::::::::::::::::::::::::
T KATO The Sup eroutburst of RZ Sagittae :::::::::::::::::::::::
R W ARGYLE Photometry and Astrometry of Variable Stars :::::::::::
P A HECKERT BVRI Photometry of CG Cygni :::::::::::::::::::
T LEBZELTER F KERSCHBAUM HD a New Semiregular
Variable ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::
C HEERLEIN Long Term Behaviour of the Eclipsing Binary PX Cephei
R M BRANLY M E BELFORT P A FRIEND W VAN HAMME
R J HIGGINS A New Ephemeris for ER Cephei :::::::::::::::::::::::::
L N BERDNIKOV O V VOZYAKOVA V V IGNATOVA Photometric
BVR Observations and New Elements of the Cepheid HD ::::::::: C
L N BERDNIKOV O V VOZYAKOVA V V IGNATOVA Photometric
BVR Observations of the Peculiar Cepheid V Lyr ::::::::::::::::::::
C
L N BERDNIKOV O V VOZYAKOVA V V IGNATOVA Photometric
BVR Observations and Classi cation of NSV ::::::::::::::::::::::
C
R WASATONIC E F GUINAN Photo electric Photometry of the
1
Red Sup ergiant Her :::::::::::::::::::::::::::::::::::::::::::::::::::
J DUSEK Photometric Investigation of Y Canum Venaticorum :::::::::
Z MUYESSEROGLU B GUROL S O SELAM Photo electric Minima of
Some Eclipsing Binaries ::::::::::::::::::::::::::::::::::::::::::::::::::
F AGERER W KLEIKAMP W MOSCHNER New Elements of V
Cygni ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::
F AGERER J HUBSCHER Photo electric Minima and Maxima of
Selected Eclipsing and Pulsating Variables ::::::::::::::::::::::::::::::::
F AGERER J HUBSCHER Photo electric Minima of Selected Eclipsing
Binaries ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::
P A HECKERT M R BEAVER K PHILLIPS Photometry of
RT Andromedae ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::
M MARTIGNONI XZ Lac NSV :::::::::::::::::::::::::::::::
P FRANK J MOSCHNER W MOSCHNER NSV First Elements
and Lightcurve ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::
QIAN SHENGBANG LIU QINGYAO YANG YULAN
GU SHENGHONG HUAN ZHANQUI New Ephemeris and Light Curves
of DD Mono cerotis ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::
QIAN SHENGBANG LIU QINGYAO YANG YULAN
GU SHENGHONG HUAN ZHANQUI The Period Behaviour
of BL Eridani ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::
L N BERDNIKOV D G TURNER Photo electric BVI Observations and
C
New Elements for the RR Lyrae Star SU Col :::::::::::::::::::::::::::::
C MAGNAN M O MENNESSIER N D MELIKIAN M H ERITSIAN
A A KARAPETIAN Photometric and Polarimetric Observations of Seven
Miras ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::
F AGERER W MOSCHNER New Type and Elements for V Cygni
J VIDAL SAINZ The New RR Lyrae Star NSV in Andromeda ::::
J VIDAL SAINZ E GARCIA MELENDO NSV a New Eclipsing
Binary System in Cancer :::::::::::::::::::::::::::::::::::::::::::::::::
A WEHLAU S M RUCINSKI JUN SHI G G FAHLMAN
I THOMPSON Discovery of an SX Phe Star in NGC :::::::::::::::
M COLLINS HBV V Her :::::::::::::::::::::::::::::::::::::
L N BERDNIKOV O V VOZYAKOVA V V IGNATOVA Photo electric
BVR Observations of the New Cepheid Variable Star GSC :::::
c
L N BERDNIKOV O V VOZYAKOVA V V IGNATOVA Photo electric
BVR Observations for the New Cepheid Variable Star GSC ::::
c
L N BERDNIKOV O V VOZYAKOVA V V IGNATOVA Photo electric
BVR Observations of the Cepheid V Cas ::::::::::::::::::::::::::::::
c
B ALBAYRAK F F OZEREN F EKMEK CI Photo electric Minima
of Four RS CVn Type Binary Systems RT And SV Cam WY Cnc
and Z Her ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::
G E BROMAGE D A H BUCKLEY A C GILMORE
J B HEARNSHAW P M KILMARTIN L C WATSON Photometry of
the Active Chromosphere Eclipsing Binary HD ::::::::::::::::::::::
AUTHOR INDEX
Agerer F Fiedler A
Frank P
Albayrak B French J
Altamore A Friend P A
Alcala J M Fu Jian Ning
Antipin S V Garcia Melendo E
Antov A P Garrigos Sanchez A
Argyle R W Gelbmann M
Balam D D Georgiev Tsv
Balona L A Gilmore A C
Bastian U Gladders M D
Beaver M R Gomez Forrellad J M
Belfort M E
Berdnikov L N Grankin K N
Grashuis R
Berthold T Gray J D
B r o I B Greiner J
Blo omer R H Grossmann V
Borissov N Gu Shenghong
Borkovits T Guarro Flo J
Born E Guinan E
Bos M G urol B
Boudreau K Haefner R
Branly R M Hambaryan V
Bregman L Hang Zhankui
Bromage G E Haefner R
Bruch A Handler G
Budding E Hearnshaw J B
Buckley D A H Heckert P A
Burns J F Heerlein C
Camp os Cucarella F Heged us T
Carrigan B Higgins R J
Collins M Huang Zhanqui
Dahm M H ubscher J
Dahlmark L Hudson G
Demartino R Hudson R
Diethelm R Ignatova V V
Dorokhov N I
Dorokhova T N Jian Shi Yang
Dumitrescu A Jun Shi
Dupuy D L Karap etian A A
Dusek J Kato T
Ekmekci F Kerschbaum F
Eritsian M H Kilmartin P M
Fahlman G G Kim S L
Kipp er T Phillips K
Kleikamp W Predom Ch
Klo chkova V G Qian Shengbang
Ko cyla D Rau S
Kohoutek L Richter G A
Kolev D Robb R M
Konstantinova Antova R Rovithis P
Kranidiotis A Rovithis Livaniou H
Krisciunas K Rucinski S M
Kunkle R Samec R G
Kusakin A V Sarounov a L
Kuschnig R Selam S O
Lebzelter T Semkov E
Lee S W Splittgerb er E
Leedj arv L Sterken C
L epez H S Tanriver M
Letsapa B A Thompson I
Liu Quingyao Tomov N
Lloyd C Tomov T V
L opez C E Tomova M
Luedeke K D Tsvetkov M
Maesano M Tsvetkova K
Magnan C Turner D G
Magoro B T Umlenski V
Makarov V Van Hamme W
Maley J A Vandenbroere J
Marshall J J Vidal Sainz J
Martinez P Viotti R
Martignoni M Vogt N
Melikian N D Vozyakova O V
Mennessier M O
Mennickent R E Walsh S E
Miin Lo oi Wasatonic R
Mikola jewski M Watson L C
Mkrtichian D E Wehlau A
Molik P Weiss W W
Montagni F
Moschner J West K W
Moschner W Wetherbee E
Wetterer Ch
M uyesseroglu Z Williams G V
Nomen Torres J Winterberg J
Oprescu G Woissol S
Ozdemir S Wolf M
Ozeren F F Yang Yulan
Paragi Zs
Pauley B
Paunzen E
INDEX OF VARIABLES
Star IBVS No Star IBVS No
RT And ES Aqr
XZ ET
BK FI
DK FK
EG FL
V GT
S Aqr R Aql
X CI
RT KP
SX OO
SZ V
WX V
AF V
AG V
AH V
AI V
AK V
AL V
AM V
AN
T Ara
AO
U
AP
W
AQ
X
AR
Y
AS
RU
AU
RW
AW
RX
AX
RY
AY
SW
AZ
SX
BB
SY
BC
SZ
BD
UW
BE
UX
BF
UY
BG
UZ
BH
VV
BI
VW
BV
VZ
CY
WW
DN
WY
DS
WZ
DX
XX
EE
XY
ER
Star IBVS No Star IBVS No
YY Ara EL Ara
YZ EM
AA EN
AB EO
AC EQ
AD ES
AF ET
AH EU
AT EW
AX EX
BF EY
BW FF
BY FI
BZ FL
CC FM
CF FN
CH FO
CL FP
CM
SS Ari
CN
RV
CO
RW
CP
AH Aur
CQ
AP
CS
AR
CT
CY
CU
GX
CV
IM
CX
KO
CY
KR
DE
MN
DF
DG
TY Bo o
DI
TZ
DK
VW
DL
XY
DM
AC
DO
CK
DP
i
DS
SV Cam
DT
TU
DW
AH
DX
AS
DZ
AW
EE
EF
WY Cnc
EG
ZZ
EI
FF
EK
Star IBVS No Star IBVS No
Y CVn YY Cet
TU YZ
VW AA
BI AC
BO AE
AF
Beta CMa
AH
X CMi
AL
AA
AU
AD
AX
BH
BB
V Car
SU Cha
SW
RZ Cas
TV
SU Col
TW
SS Com
GT
UX
DK
CC
OX
HY
V
RW CrB
V
SZ
V
V
RT Cyg
V
WZ
V
XZ
CG
V Cen
CH
T Cep
DK
VW
DM
WW
GO
XX
KR
AH
MR
CW
V
EF
V
EK
V
EM
V
ER
V
GK
V
PK
V
V
V
T Cet
V
RT
V
SV
V
TW
V
UU
V
UV
V
VW
V
VY
V
Star IBVS No Star IBVS No
V RX Gru
V RY
V RZ
V ST
SU
TT Del
SV
TY
SW
YY
SX
DX
SY
EG
SZ
EX
TV
FZ
TW
GG
TX
AB Dor
TY
UV
R Dra
UX
SW
UY
TZ
UZ
UX
VW
VZ
VY
XZ
WW
AG
WX
BX
WY
CV
WZ
EF
ZZ
RT Equ
AA
AB
UX Eri
AD
YY
AE
BK
AF
BL
AG
BV
AI
SS For
AK
SV
AM
TT
AN
RW Gem
AQ
SZ
AR
KV
AS
AU
R Gru
AZ
T
BB
V
BE
W
BI
Y
BK
RT
BN
RU
BO
RV
PI
RW
Star IBVS No Star IBVS No
Z Her V Lyr
2
RX Delta
TX
AQ Mon
UX
DD
VZ
NS
AK
V
CC
X Oph
CT
V
DI
V
DL
V
DY
V
HS
V
LS
V
PW
V HBV
CP Ori
1
Alpha
ER
FT
AV Hya
Alpha
FG
U Peg
SW Lac
VV
XZ NSV
VZ
AR
BB
CZ
BF
EM
BN
FK
BO
HL
BP
V
DH
ST Leo
DI
UV
DY
UZ
GH
VZ
RT Per
XY h ll
SX
XZ
AG
AA
BP
AG
HZ
AL
IM
AP
IQ
RT LMi
KN
EH Lib V
V
RW Lyn
V
TV
b
RZ Lyr
T Phe
GS
V
V
RR
V
RU
V
Star IBVS No Star IBVS No
RV Phe AW Phe
RW AX
SW AY
SX AZ
SY
RU Psc
SZ
RY
TV
SS
TW
UV
TX
VZ
TY
AQ
TZ
R PsA
UU
S
UV
U
UX
V
UY
W
UZ
X
VV
Y
VW
Z
VX
RR
VY
RS
VZ
RT
WW
RU
WX
RW
WY
RX
WZ
RZ
XX
SS
XY
ST
XZ
SU
YY
SW
YZ
SZ
ZZ
TT
AA
TU
AC
TV
AD
TW
AG
TX
AI
AK
RZ Sge
AL
CU
AM
CW
AN
FG
AO
V Sgr
AP
AQ
R Scl
AR
S
AS
T
AT
U
AU
V
AV
W
Star IBVS No Star IBVS No
X Scl AL Scl
Y AM
Z AN
RR AO
RT
RS Sct
RU
CC Ser
RV
CW
RX
RY
CN Tau
RZ
GR
SS
V
ST
W UMa
SU
TX
SV
UY
SW
VY
SZ
AW
TU
TV
S UMi
TW
RR
UV
R Vir
UW
AX
UY
AZ
UZ
BC
VV
HW
VW
BK Vul
VX
VY
GSC
VZ
GSC
WW
GSC
WX
GSC
WY
GSC
WZ
HBV V Her
XX
XY
HD
XZ
HD
YY
HD
YZ
HD
ZZ
HD
AA
HD
AB
HD
AC
HD
AD
HD
AE
HD
AF
HR
AG
AH
LD LD
AI
LkCa LkCa
AK
Star IBVS No Star IBVS No
LkCa NSV
LkCa NSV
LkCa LkCa NSV
LkCa NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
NSV
Star IBVS No Star IBVS No
NSV NSV
NSV XZ Lac NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV NSV
NSV
PG
NSV
PG
NSV
PG
NSV
RX J
NSV
NSV
Sup ernovae
NSV
SN C
NSV
SN ab
NSV
Variables in clusters
NSV
in NGC V V
NSV
New Variables
NSV
in CrB eld Nos
NSV
GSC
NSV
GSC
NSV
GSC
NSV
GSC
NSV
GSC
NSV
HD
NSV
HD
NSV
HD
NSV
HD
NSV
HD
NSV
HD
NSV
HD
NSV
in Her eld Nos
NSV
Nos
NSV
HR
NSV
LD LD
NSV
in NGC V
NSV
in Oph eld Nos
NSV
Nos
NSV
Star IBVS No
PG
PG
PG
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
PULSATION OF HD AND HD
We present two new variable Bo otis stars as a result of our survey to detect variability
among Bo otis stars Paunzen The general prop erties of this group are describ ed
in Weiss et al
HD was classi ed as A I I I I I w by Houk The Str omgren and Geneva
colors Gray Olsen and Rufener on the other hand are typical for a MS star
and very similar to HD Hauck and Weiss et al Recent sp ectroscopic
observations seem to con rm the Bo otis character of HD The photometric obser
vations were p erformed in the night of May with the meter Lowell telescop e
at CTIO observer E Paunzen An integration time of seconds in Str omgren v and
b was chosen We used HD V A V as comparison star Figure shows the
light curves of b oth stars in Str omgren b Pulsation of HD is evident although the
data set is rather short We estimate a p erio d of minutes and an amplitude of mmag
in Str omgren b Figure
HD was classi ed by Gray as The K line and the metallic line sp ectrum
are similar to the A standards except that Mg app ears weak The hydrogen lines
show very broad wings with slightly weak cores St urenburg derived for the
elements Mg Ti Cr Fe and Ba an underabundance of a factor compared to the Sun
Iliev Barzova estimated the following stellar parameters
log Ag e T K log g
ef f
The observations were made with the meter telescop e at McDonald observatory ob
server G Handler during the nights of and Aug An integration time
of seconds in Str omgren v and b was chosen We used HD V Hg Mn
star and HD V F as comparison stars Both proved to b e constant
HD was susp ected to b e variable by Rufener Bartholdi They gave
an upp er limit for constancy of mmag in V Figure shows the light curves of all
stars for the second night in Str omgren b There are still some sky variations at the end
of the night The intrinsic light variations are very small but there is no doubt ab out
variability of HD We infer a p erio d of minutes and an amplitude of mmag
in Str omgen b Figure shows the amplitude sp ectra for HD HD and the
di erential data
The p erio ds determined for HD and HD are consistent with exp ected
p erio ds for A type stars at the MS Stellingwerf An age determination with the
to ols of asteroseismology would b e very helpful to establish the evolutionary stage of
Bo otis stars
HD 83041 - HD 82709 10 mmag(b)
HD 83041
HD 82709
0.50 0.52 0.54 0.56 0.58 0.60 0.62 0.64
JD 2449840+
Figure Light curves for HD HD and the di erential data in Str omgren b
0.004
HD 83041 - HD 82709 HD 83041 HD 82709 0.003
0.002
semi-amplitude [b] 0.001
0.000
0 20 40 60 80 100
frequency [c/d]
Figure Amplitude sp ectrum for HD HD and the di erential data as
shown in Figure
HD 221756
HD 223636 12 mmag (b)
HD 220575
0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16
JD 2449940.8+
Figure Light curves for HD HD and HD for the second night in
Str omgren b
0.004
HD 221756 - HD 220575 HD 221756 HD 220575
0.003
0.002
semi-amplitude [b] 0.001
0.000
0 20 40 60 80 100
frequency [c/d]
Figure Amplitude sp ectrum for HD HD and the di erential data as
shown in Figure
Acknowledgement This research was done within the working group Asteroseismology
AMS Computing resources and nancial supp ort for this international collab oration were
provided by the Fonds zur F orderung der wissenschaftlichen Forschung pro ject S
AST and the Ho chschuljubil aumsstiftung der Stadt Wien Bo otis Sterne GH ac
knowledges partial nancial supp ort by the Austrian Zentrum f ur Auslandsstudien This
research has made use of the Simbad database op erated at CDS Strasb ourg France
E PAUNZEN
G HANDLER
Institut f ur Astronomie
T urkenschanzstra e
A Wien Austria
e mail paunzen astro ast univie ac at
e mail handler astro ast univie ac at
References
Gray R O AJ
Gray R O Olsen E H A AS
Hauck B A A
Houk N University of Michigan Catalogue of Two Dimensional Sp ectral Types
for the HD Stars Volume I I I Astronomy Dept Univ Mich Ann Arb or Michigan
Iliev I K Barzova I S A A
Paunzen E IBVS No
Rufener F Catalogue of stars measured in the Geneva Observatory Photometric
System th ed Geneva Observatory
Rufener F Bartholdi P A AS
Stellingwerf R F ApJ
St urenburg S A A
Weiss W W Paunzen E Kuschnig R Schneider H A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
NONVARIABILITY AMONG Bo o STARS I
ESO AND DATA
In we started an extensive survey for pulsation in Bo otis stars The Bo otis
stars are a group of metal p o or p opulation I A type stars Weiss et al with broad
and often shallow hydrogen lines which are probably caused by a gas shell Two theories
exist concerning the evolutionary status of this group In the rst case di usion 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 would b e just arriving at the ZAMS Turcotte Charb onneau
Therefore their lo cation in the Hertzsprung Russell diagram and hence their evolu
tionary status is still controversial Iliev Barzova Keeping these contradicting
theories in mind it is imp ortant to discover pulsation among Bo otis stars b ecause
pulsation allows to derive stellar structure parameter by applying the to ols of asteroseis
mology We have chosen for our survey candidates from Renson et al and Gray
Corbally These stars were observed with the classical technique using at least
one comparison star and two lters Str omgren v and b All observations were corrected
for the sky background deadtime and extinction Up to now we found new pulsating
Bo otis stars e g Paunzen In a series of IBVS notes we want to present data of
all photometrically constant Bo otis candidates
In this pap er we discuss data observed at the cm ESO telescop e observer E
Paunzen from June th to July th and July th to July st Table lists all
observed Bo otis and comparison stars with the night and duration of the observations
The amplitude sp ectra and sp ectral window Figures to were calculated with a
standard Fourier technique Breger Due to the limitation of the IBVS format we
present in these gures the amplitude sp ectra and sp ectral windows for the di erential
photometry of the Bo otis and one comparison star up to the Nyquist frequency The
other comparison star if observed was constant as well In case of observations in more
than one night we merged the data of all nights The upp er level of nonvariability is
typically mmag in Str omgren b
It is evident from Table and the gures that the nights have b een of di erent quality
Due to the noise and the limitation of the data set we cannot exclude variability on
a low amplitude level b ecause we can only give an upp er limit for it However until
proven otherwise we assume these stars to b e constant The p erio ds of variable Bo otis
stars detected so far range typically from to minutes From the PLC relation
of Stellingwerf we would exp ect a fundamental p erio d of a radial mo de for early
A type stars at the MS of ab out to minutes to c d
Table Program and comparison stars this comparison star is used for the gure
Star Durchm JD hours m Sp ec Upp er level b
V
HD CD Bo o
HD CD F IV
HD CD Bo o
HD CD A IV
HD CD B I I I
HD CD Bo o
HD CD F V
HD CD A V
HD CP Bo o
HD CP B V
HD CD Bo o
HD CD F V
HD CD A V
HD BD Bo o
HD BD F I I I
HD BD A IV
HD CP Bo o
HD CP Am
HD CD Bo o
HD CD Bo o
HD CD A V
HD CD Bo o
HD CD F
HD CD F V
1.0 0.8 0.6 0.4
spectral window 0.2 0.0 0.004 HD 319 HD 141851 0.003
0.002
0.001 semi-amplitude [b] 0.000 0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140
frequency [c/d] frequency [c/d]
Figure Amplitude sp ectrum and sp ectral window for the di erential data of HD and HD
in Str omgren b
1.0 0.8 0.6 0.4
spectral window 0.2 0.0
0.004 HD 143148 HD 145782
0.003
0.002
0.001 semi-amplitude [b] 0.000 0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140 160
frequency [c/d] frequency [c/d]
Figure Amplitude sp ectrum and sp ectral window for the di erential data of HD and
HD in Str omgren b
1.0 0.8 0.6 0.4
spectral window 0.2 0.0 0.004 HD 154153 HD 179791 0.003
0.002
0.001 semi-amplitude [b] 0.000 0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140
frequency [c/d] frequency [c/d]
Figure Amplitude sp ectrum and sp ectral window for the di erential data of HD and
HD in Str omgren b
1.0 0.8 0.6 0.4
spectral window 0.2 0.0 0.004 HD 193256 HD 193281 0.003
0.002
0.001 semi-amplitude [b] 0.000 0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140
frequency [c/d] frequency [c/d]
Figure Amplitude sp ectrum and sp ectral window for the di erential data of HD and
HD in Str omgren b
1.0 0.8 0.6 0.4
spectral window 0.2 0.0 0.004 HD 188164 HD 204041 0.003
0.002
0.001 semi-amplitude [b] 0.000 0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140
frequency [c/d] frequency [c/d]
Figure Amplitude sp ectrum and sp ectral window for the di erential data of HD and
HD in Str omgren b
Acknowledgement This research was done within the working group Asteroseismology
AMS Computing resources and nancial supp ort for this international collab oration were
provided by the Fonds zur F orderung der wissenschaftlichen Forschung pro ject S
AST and the Ho chschuljubil aumsstiftung der Stadt Wien Bo otis Sterne This re
search has made use of the Simbad database op erated at CDS Strasb ourg France
E PAUNZEN
W W WEISS
R KUSCHNIG
Institut f ur Astronomie
T urkenschanzstra e
A Wien Austria
e mail paunzen astro ast univie ac at
References
Breger M Communications in Asteroseismology
Gray R O Corbally C J AJ
Iliev I K Barzova I S A A
Paunzen E IBVS No
Renson P Faraggiana R B ohm C Bul l Inform CDS
Stellingwerf R ApJ
Turcotte S Charb onneau P ApJ
Weiss W W Paunzen E Kuschnig R Schneider H A A
ERRATUM
In Table of the IBVS No several cross identi cations have b een erroneously given
The correct version of the Table is given b elow
Table Program and comparison stars this comparison star is used for the gure
Star Durchm JD hours m Sp ec Upp er level b
V
HD CD Bo o
HD CD F IV
HD BD Bo o
HD BD A IV
HD BD B I I I
HD CD Bo o
HD CD F V
HD CD A V
HD CP Bo o
HD CP B V
HD CD Bo o
HD CD F V
HD CD A V
HD BD Bo o
HD BD F I I I
HD BD A IV
HD CP Bo o
HD CP Am
HD CD Bo o
HD CD Bo o
HD CD A V
HD BD Bo o
HD BD F
HD BD F V
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
PHOTOMETRY OF SV CAMELOPARDALIS
SV Camelopardalis SAO in the catalog of Strassmeier et al is a
member of the short p erio d group of eclipsing RS CVn systems Budding and Zeilik
rst mo deled the starsp ots on this system and Zeilik et al mo deled the starsp ots
for data available over the previous half century Sarma et al have also mo deled
the sp ots on this system Continuing this work I obtained BVRI light curves during
and mo deled the starsp ot structure I observed SV Cam on the nights of and
January and and February with the San Diego State University cm telescop e
on Mt Laguna The photometer has a Hamamatsu R tub e co oled to C
and op erated at V Following Patk os I used SAO BD
HD as the comparison star In over seven years of photometry of SV Cam Patk os
found no evidence of variability of this comparison star Using Landolt standard stars
I transformed the data into di erential magnitudes in the standard Johnson Cousins
system Figures and show the di erential star comparison magnitudes in the BVRI
bands I mo deled the data with the Information Limit Optimization Technique ILOT
of Budding and Zeilik I started with the various stellar and orbital parameters
from Budding and Zeilik and Zeilik et al to p erform initial ts to the data
The ILOT programs then subtract eclipse e ects from the data and t starsp ots to the
remaining distortion wave These SV Cam data t b est with two sp ots Figure shows
the V band sp ot t The results in degrees are
Sp ot ts
B band V band R band I band
Longitude
1
Latitude xed
1
Radius
1
Longitude
2
Latitude
2
Radius
2
2
The sp ot mo dels of Zeilik et al show that over a year span one fairly large high
latitude sp ot tends to t the data These data are t b est with two low latitude
sp ots an apparently unusual o ccurrence for this system Both sp ots are however lo cated
in the active longitude b elts ALBs at roughly and noticed by Zeilik et al
After nding the b est sp ot ts the ILOT programs allow one to subtract the
sp ot e ects to p erform clean ts to the data Figure shows the initial and clean ts for
the V band For the clean ts I get
Clean ts
B band V band R band I band
U
L
1
k r r
2 1
r
1
i deg
L
2
q M M
2 1
2
Figure B and V light curves of SV Cam in Jan Feb
Figure R and I light curves of SV Cam in Jan Feb
Figure V band sp ot t for Jan Feb
Figure SV Cam Jan Feb Initial and clean ts for the V band
The clean t parameters are as de ned by Budding and Zeilik L and L the
1 2
fractional luminosities of the primary and secondary stars sum to the unit of light U
in the absence of a third light Rainger et al and Sarma et al nd
evidence for a third comp onent in this system but I was unable to nd evidence for a
third light from my data Note that the secondary is much fainter than the primary if
the third comp onent were fainter than the secondary it would not b e detectable with this
photometry The primary and secondary radii r and r are in units of the semi ma jor
1 2
axis of the orbit and i is the orbital inclination The mass ratio from these mo dels is
somewhat lower than the usual value of to Budding and Zeilik Sarma et al
Patkos and Hemp elmann Otherwise these clean ts agree fairly well with the
values found by Zeilik et al
I thank Ron Angione for scheduling very generous amounts of observing time at Mt
Laguna I received supp ort from the American Astronomical So ciety Small Grants Pro
gram for this work I also acknowledge b oth nancial supp ort and a Faculty Scholarly
Development Assignment Program Leave from Western Carolina University
P A HECKERT
Dept of Chem Physics
Western Carolina University
Cullowhee NC
USA
References
Budding E and Zeilik M Astrophys J
Patk os L Comm Konkoly Obs No
Patk os L and Hemp elmann A Astron Astrophys
Rainger P P Hilditch R W and Edwin R P MNRAS
Sarma C V S R Sarma M B K and Sanwal N B J Astrophys Astron
Sarma C V S R Vivekananda Rao P and Sarma M B K J Astrophys Astron
Strassmeier K et al Astron Astrophys Suppl
Zeilik M De Blasi C Rho des M and Budding E Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
PERIOD CHANGES IN V OPHIUCHI
The eclipsing binary V Oph BD HD GSC
h m s 0 00
Sp F V V mag is a relatively well known W UMa
max
type binary system with a p erio d of day This bright variable star b elongs to the
nearest binaries and therefore it was also included into the Hipparcos program of parallax
measurement from space Dworak Oblak It was discovered to b e a variable
star by Rigollet the rst photo electric measurements were presented by Binnendijk
Later on photometric measurements were obtained by Wilson O Toole
Lafta Grainger and Niarchos The recent photo electric times of
minima were published by Han zl Demircan et al and Agerer
H ubscher
Our new CCD photometric observations of V Oph were carried out during August
and Octob er at Ond rejov Observatory Czech Republic using a cm re ecting
telescop e with a CCD camera SBIG ST at the primary fo cus The measurements
were done using the standard Johnson V lter with s exp osure time One additional
time of primary minimum was obtained in Octob er at the R Szafraniec Observatory
Metzerlen Switzerland using a cm Cassegrain telescop e with the same CCD camera
and without any lter
The star GSC BD V mag used also by Binnendijk
and other observers on the same frame as V Oph served as a comparison
star All CCD data were reduced using a software developed at Ond rejov Observatory
by P Pravec and M Velen Pravec et al The times of primary minima and their
error were determined as mean values the Kwee van Woerden metho d and the
parab olic t into the data le They are presented in Table In this table N stands for
the number of measurements used for the determination of minimum time The ep o chs
were calculated using the linear light elements given in GCVS Kholop ov et al
Pri Min HJD E
The p erio d changes of V Oph were studied by means of O C diagram analysis
We to ok into consideration all photo electric times of minima found in the literature as
well as the rst visual minimum obtained by the discoverer E The other
numerous visual estimations were not included due to the large scatter of the data
Table New precise times of primary minima of V Oph
JD Hel Error N Ep o ch Observatory
d
Ond rejov
Ond rejov
Metzerlen
Figure O C residuals for the times of minima of V Oph with resp ect to the linear light elements
The dashed curve represents the parab olic approximation The individual primary and secondary
photo electric times are denoted by circles the rst visual estimation by triangle
A total times of minimum light were incorp orated in our analysis with secondary
eclipses among them We derived new quadratic light elements by the least squares
metho d
Pri Min HJD E E
It indicates that the p erio d of V Oph is increasing From these elements we obtained
P
The O C residuals for all times of minimum with resp ect to the linear
P
ephemeris are shown in Figure The non linear t corresp onding to the calculated
elements is plotted as a dashed curve
Subtracting the parab olic term in light elements which could b e caused by a mass
transfer or mass loss from the system the O C diagram can b e plotted Signi cant
quasi sinusoidal variation of these residuals are easily seen in Figure This additional
phenomenon can b e caused by the presence of a third b o dy in this system light time
e ect or by magnetic activity of the comp onents which was describ ed recently by Ap
plegate The preliminary p erio d of a third b o dy orbit or a magnetic cycle could
b e P ' days years
Figure O C residuals for the times of minimum of V Oph after subtracting the parab olic term
2
in light elements The quasi sinusoidal pro le with the p erio d of ab out years is remarkable
No rm solution of the present O C diagram could b e given b ecause the predicted
p erio d is not covered su ciently by precise photo electric measurements More high accu
racy timings of this eclipsing binary are necessary in the future to expand the time span
for b etter analysis of b oth of these phenomena
Acknowledgement This work has b een supp orted in part by the Grant Agency of the
Czech Republic grant No and by the ESO C EE Programme grant No
A We gratefully acknowledge the assistance of Dr Roger Diethelm R Szafraniec
Observatory Metzerlen in providing for our CCD observations We are thankful to Mr
Franz Agerer BAV for extracting all timings of V Oph from the Lichtenknecker s
database This research has made use of the SIMBAD database op erated at CDS Stras
b ourg France
Petr MOLIK
Marek WOLF
Stef anikObservatory
Lenka SAROUNOVA
Pet r n
Astronomical Institute
CZ Praha
Charles University Prague
Czech Republic
Sv edsk a
CZ Praha
Czech Republic
Internet wolf earn cvut cz
References
Agerer F H ubscher J Inf Bul l Var Stars No
Applegate J H Astrophys J
Binnendijk L Astron J
Demircan O Tanriver M Devlen A et al Inf Bul l Var Stars No
Dworak T Z Oblak E Inf Bul l Var Stars No
Dworak T Z Oblak E Inf Bul l Var Stars No
Han zl D Inf Bul l Var Stars No
Han zl D Inf Bul l Var Stars No
Kholop ov P N et al General Catalogue of Variable Stars Vol I I Nauka Moscow
Kwee K K Van Woerden H Bul l Astron Inst Neth
Lafta S J Grainger J F Astrophys Space Sci
Niarchos P G Inf Bul l Var Stars No
Niarchos P G Astrophys Space Sci
Pravec P Tich y M Tich a J Moravec Z V avrov a Z Velen M Planet Space
Sci
Rigollet R l Astronomie
Wilson R E O Toole W Publ Astron Soc Paci c
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
OPTICAL OBSERVATIONS OF THE ACTIVE STAR FF CANCRI
The star FF Cancri GSC was discovered to b e an eclipsing binary by Pravec
who found it to have a color of V R and a brightness V
The automated m telescop e Cousins R lter and CCD camera of the Climenhaga
Observatory of the University of Victoria Robb and Honkanen were used to make
photometric observations of FF Cancri The frames were bias subtracted and at elded
in the usual manner using IRAF The magnitudes were found from ap erture photometry
using the PHOT package The x y pixel co ordinates of each star for photometry were
found from insp ection of a few frames and these p ositions were used as starting p oints
for the Gaussian centering option which precisely centered the arc second ap erture on
each star for each frame
From the Hubble Space Telescope Guide Star Catalog Jenkner et al the co
h m s 0 00
ordinates and magnitudes of the comparison star are RA Dec
h m s 0 00
V and of the check star are RA Dec V J The
standard deviation of the di erence b etween the check and the comparison star during a
m m
night ranged from : to : The mean and standard deviation of the six nightly
m m
mean di erential R magnitudes are : : ensuring the constancy of b oth com
parison and check stars at this level The precision of the di erential variable star minus
comparison star measurements are exp ected to b e at this level Due to the small eld of
view rst order di erential 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 the R magnitude to a standard system
Photometric observations were made b etween the nd and the th of February
UT By the metho d of Kwee and Van Woerden Helio centric Julian Dates of primary
d d d
minima were found to b e : : and : and secondary
d d
minima o ccurred at : and : The uncertainty in the times of
d
minima were formally ab out : days but this estimate do es not include an allowance
for the asymmetry in the minimum and thus the true uncertainty is larger These min
d
ima unambiguously determine the orbital p erio d to b e ab out : Pravec s data
include the sharp shoulder at the end of the primary eclipse at a time we estimate to b e
d d d
: We have similar observations at : and : requiring
an integral number of cycles to have elapsed gives us the following ephemeris
d d
HJD of Primary Minima : : E
d d
: :
1
IRAF is distributed by National Optical Astronomy Observatories which is op erated by the Asso ciation of Universities for Research in Astronomy Inc under contract to the National Science Foundation
Plots of the light curve for p erio ds corresp onding to one cycle less and one cycle more
than this p erio d lo ok signi cantly noisier
A plot of the di erential R magnitudes phased at this p erio d is shown in Fig
ure with di erent symbols for each of the di erent nights The obvious out of eclipse
mo dulation of the light curve indicates that one or b oth of the stars are sp otted since
proximity e ects would b e symmetrical ab out the minima The p oints marked with a
represent data from a night days earlier than the other data and show a shift of a few
hundredths of a magnitude in the depth of the secondary minimum and at the b eginning
of the secondary minimum indicating that the co ol sp ots are probably on the primary
star
Figure Light curve of di erential R data of FF Cancri
The V R color of Pravec and a cursory insp ection of a sp ectrum taken with
the Dominion Astrophysical Observatory m telescop e indicate approximately a K V
sp ectral type for the primary star Using Binmaker Bradstreet and a temp er
ature of K for the primary star of the system we have constructed a mo del light
curve which ts our observed light curve and can b e seen in Figure Using alb edo
and limb darkening co e cients appropriate for the assumed sp ectral types the b est t
we found was for an approximately K V secondary star in an orbit inclined at Two
large sp ots on the primary star are necessary to t the out of eclipse variations and this
is consistent with a presumably synchronous rotation p erio d and the temp erature of the
stars A dimensional diagram of the system is shown in Figure Note that this is not
a unique solution in particular the sp ot latitude is not well determined
1.00
0.90
Flux 0.80
0.70
0.60
0.00 0.25 0.50
Phase
Figure Light curve and a p ossible Binmaker mo del for FF Cancri
Figure Three dimensional diagram of a p ossible Binmaker mo del of FF Cancri at phase
Further measurements will b e very valuable to increase our knowledge of this imp ortant
system Photometric monitoring will b e of interest since the changes in the light curve
shap e are probably due to di erential rotation or active region evolution Radial velocity
measurements will b e very imp ortant for the determination of the absolute dimensions of
the system the distance and the gamma velocity A careful sp ectral classi cation would
con rm the temp erature of the primary star and check for the presence of Ca H K
emission We note that the star is in the direction of Praesep e in the sky and current
estimates of its distance are to o uncertain to rule out membership in that cluster so prop er
motion and the radial velocity measurements will test for the star s membership in the
cluster Although FF Cancri has not b een detected in X rays or the extreme ultraviolet
EUV Pounds et al Malina et al it should b e exp ected to b e a source
since it has large active regions The eclipse of these active regions by the secondary star
would help to measure the spatial extent of the emitting region
R M ROBB
M D GLADDERS
Climenhaga Observatory
Dept of Physics and Astronomy
University of Victoria
Victoria BC Canada V W P
Internet robb uvastro phys uvic ca
Internet gladders uvastro phys uvic ca
References
Bradstreet D H Binary Maker User Manual Contact Software Norristown
PA USA
Jenkner H Lasker B Sturch C McLean B Shara M Russell J AJ
Kwee K K and Van Woerden H Bul l Astr Inst Neth
Malina R F et al AJ
Pounds K A et al MNRAS
Pravec P IBVS No
Robb R M and Honkanen N N in A S P Conf Ser Automated Telescopes
for Photometry and Imaging ed Adelman Dukes and Adelman
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
CONFIRMATION OF THE CLASSIFICATION OF A NEW
TYCHO VARIABLE HD IS A DAY CEPHEID
The Hipparcos mission of ESA is mainly an astrometric pro ject Its photometric
comp onent however is exp ected to discover thousands of new variables For a description
of the mission see Perryman and references therein A rst list of bright stars
which were discovered to b e variable in the course of the data reductions for the Tycho
exp eriment on the Hipparcos satellite was published in IBVS No Makarov et al
HD GSC is one of them In IBVS No the star GSC
was erroneously included in the list of newly discovered variables In fact its variability
had already b een known It is RY Arae This error was p ointed out by H Mauder
T ubingen
The Tycho observations of any particular star are very unevenly distributed in time
Therefore it is usually di cult to derive the type and light curve elements for a newly
discovered variable This is why in the fall of a call for observations of the new
variables was issued to amateurs
Within a few weeks visual observations by M Dahm and E Born showed that HD
is a Cepheid with a p erio d of ab out days This information prompted photo electric
observations by F Agerer from which the light curves in Figure resulted along with an
improved estimate of the p erio d days The Tycho observations in the B
T
photometric band folded with this p erio d are shown in Figure They to o con rm the
classi cation and p erio d determination The Tycho observations were collected b etween
and Small groups of nearly simultaneous Tycho observations were binned
b efore plotting in Figure in order to reduce the scatter The photo electric data in
Figure were collected around the end of Combining the two normal ep o chs for
the maxima from these two widely separated data sets we nd the following light curve
elements for HD
JD max E
These values were derived from a combination of the B and V data The maximum
o ccurs almost simultaneously in the two channels Formal standard errors are given in the
line b elow the light curve elements The normal ep o ch given refers to Agerer s data Fig
The corresp onding normal maximum ep o ch from the Tycho data is JD
The variability of HD HIP was indep endently discovered from the data
of the Hipparcos main instrument Compared to Tycho this instrument gives photometry
with much higher precision and a somewhat higher number of individual measurements
Therefore it was p ossible to indep endently derive a type and p erio d Thus Turon
van Leeuwen also announced HD to b e a Cepheid of ab out day p erio d
but without giving complete light curve elements According to van Leeuwen private
communication b est t elements from the Hipparcos main instrument alone are
Figure Photo electric B and V light curves of HD collected around the end of The
observations were done with F Agerer s private m automatic telescop e The photometer was
equipp ed with an unco oled EMI A tub e and Schott lters for B and V The diaphragm was in
diameter PPM F served as comparison star and PPM K to check its constancy
Figure The TYCHO data in the B channel collected b etween and Figures and are
T
folded light curves based on an assumed p erio d of days
JD max E
Combining the reference ep o ch from the Hipparcos main instrument with the normal
ep o ch from the ground based photometry we nd as the currently b est estimate of the
elements of HD
JD max E
It is surprising that such a bright continuously variable star with an amplitude as
large as mag in V and mag in B has remained undetected for so long
Acknowledgements The Tycho pro ject was supp orted by Bundesministerium f urFor
schung und Technologie Deutsche Agentur f urRaumfahrtangelegenheiten DARA Pro
jects and and by the Danish Space Board Results from the Hippar
cos pro ject are based on the collab orative e ort of many scientists and engineers scattered
all over Europ e The unpublished Hipparcos main grid results on HD communi
cated to us by F van Leeuwen greatly improved the precision of the p erio d determination
Ulrich BASTIAN
Eckhard BORN
Franz AGERER
Michael DAHM
Volkmar GRO MANN
Valeri MAKAROV
Astronomisches Rechen Institut M onchhofstr D Heidelb erg Germany
Kitzinger Str D Erlangen Germany
Dorfstr D Tiefenbach Germany
Wilhelm Liebknecht Str D Bremen Germany
Institut f ur Astronomie und Astrophysik Astronomie Waldh auser Str
D T ubingen Germany
Cop enhagen University Observatory Juliane Maries Vej DK Cop enhagen OE Denmark
References
Makarov V et al IBVS No
Perryman M A C Nature
Turon C van Leeuwen F IAU Coll Astrophysical Applications of Stellar Pulsation ASP Conference Series Vol
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
NEW TIMES OF MINIMA OF THE ECLIPSING
BINARIES i BOOTIS AND VW CEPHEI
The eclipsing variable stars i Bo o and VW Cep are two well observed active close
binaries of W UMa type Here we present new times of minima for these two systems
determined from our photo electric observations made during
i Bo otis
The eclipsing binary i Bo o is the fainter companion B C of the close visual binary
ADS Its light curves are characterized by active and quiet intervals and its
p erio d is variable e g Bergeat et al Rovithis and Rovithis Livaniou Oprescu
et al Gherega et al
New photo electric observations of the system were made during two nights in April as
well as during one in May and two in August The observations in April were made
with the two beam multi mode nebular stellar photometer of the National Observatory
of Athens attached to the inch Cassegrain re ector at the Kryonerion Astronomical
Station while those in May and August with an EMI B type photo cell attached to
the cm Cassegrain telescop e of the Bucharest Observatory
From our observations of i Bo o six new minima times were derived and are presented
in Table I
Table Photo electric minima of i Bo otis
Hel JD Min Filter O C O C O C
I II III
days days days
II V
II B
I V
I B
I V
I B
I V
I B
I U
II V
II B
II U
I V
I B
I U
In Table the residuals O C O C O C have b een calculated using
I II III Kwee Van Woerden s metho d and according to the following ephemeris formulae
Figure The latest part of the O C diagram of i Bo o based on Duerb eck s
ephemeris formula
Figure The latest part of the O C diagram of VW Cep based on Navratil s ephemeris formula
I Min I J D E
Duerb eck
I I Min I J D E
Rovithis and Rovithis Livaniou
I I I Min I J D E
Oprescu et al
From the recent part of the O C diagram of i Bo o which is presented in Figure
based on Duerb eck s ephemeris and corresp onding to the last years and from
a comparison of the O C values presented in Table with those of Rovithis Livaniou et
al we can see that the p erio d of i Bo o is continuously increasing
VW Cephei
The eclipsing binary VW Cep is a member of a triple system Hershey Its light
curves show temp oral variation on short time scales from night to night e g Kwee
Kreiner Winiarski as well as on long time scales e g Karimie Kotarska
Glownia Bradstreet Guinan
Photo electric observations of VW Cep were made during nine nights in August
in September and in Octob er at the Bucharest Observatory using the same
instruments as for the observations of i Bo otis
Table New minima of VW Cephei
Hel JD Min Filter E O C O C
I II
Type days days
II V
II B
II U
I V
I B
I U
II V
II B
II U
II V
II B
II U
I V
I B
I U
I V
I B
I U
II V
II B
II U
From our observations seven new minima times were derived and are presented in Table
where the residuals have b een found using Kwee Van Woerden s metho d and
the C s have b een calculated according to the ephemeris
Min I J D E I
Navratil
and its improvement
Min I J D E I I
Aluigi et al
From the recent part the O C diagram of VW Cep presented in Figure corresp ond
ing to the last years and based on Aluigi et al s ephemeris it is clear that the
orbital p erio d of the system is decreasing
Moreover from the O C values of Table one can notice that b etter results are
obtained from the improved ephemeris that of Navratil s which corresp onds to
a smaller p erio d for VW Cep indicating again that the p erio d of the system is continuously
decreasing
Acknowledgements This work was partly nancially supp orted by a bilateral Greek
Romanian co op eration program of the Ministry of Industry Energy and Technology
P ROVITHIS
G OPRESCU
Astron Inst
A DUMITRESCU
Athens National Obs
Astron Inst
Athens Greece
Bucharest Obs
Bucharest Romania
H ROVITHIS LIVANIOU
Section of Astroph
Astron Mechanics
Dept of Physics
Athens University Greece
e mail elivan atlas uoa gr
References
Aluigi M Galli G Gaspani A IBVS No
Bergeat J Lunel M Van t Veer F A A
Bradstreet D Guinan E in Active Close Binaries Ed C Ibanoglu Kluwer
p
Duerb eck H W IBVS No
Gherega O Farkas L Horv ath A IBVS No
Hershey J L ApSS
Karimie M T ApSS
Kotarska I Glownia Z AN
Kreiner J M Winiarski M Acta Astron
Kwee K K Bul l A I Neth
Kwee K K Van Woerden H Bul l A I Neth
Navratil M IBVS No
Oprescu G Suran M D Popescu N IBVS No
Oprescu G Suran M D Popescu N IBVS No
Rovithis P Rovithis Livaniou H A ASS
Rovithis Livaniou H Rovithis P Oprescu G Dumitrescu A IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
NEW ELEMENTS FOR THE ECLIPSING BINARY ZZ Cnc
ZZ Cnc HD A BD BV was discovered an as Algol
type eclipsing binary by Strohmeier The GCVS Kholop ov et al contains
rst elements derived by Strohmeier a b
Min J D E
EA m
pg
Since the p erio d is rather long further photometric observations of the star were not
numerous Only one minimum has b een published up to now Isles
Brightness of ZZ Cnc was estimated using the photographic plates of the Sonneb erg
Sky Survey to check the validity of the ab ove elements These elements were found to b e
not correct In the pap er of Strohmeier only minima with even numbers of ep o ch were
listed
The magnitude values determined from plates covering the years have
p ointed out to double the value of the p erio d found by Strohmeier The light curve folded
on the new p erio d is shown in Figure Period analysis of that material by means of
a metho d published by Renson has b een done Figure con rming the ab ove
conclusion
A weighted least squares t yields the following linear ephemeris
d
Min J D : E
EA m D P
pg
Table Observed times of minima for ZZ Cnc ep o chs and residuals
Minimum Ep o ch O C Weight Observer
JD
Strohmeier
Berthold
Figure Photographic light curve of ZZ Cnc plotted using the elements Photographic magnitudes
were obtained by a photographic photometer and refer to the Harvard Groningen SA
Figure Periodogram days of ZZ Cnc
The minimum of Isles derived from visual observations has not b een considered
This pap er could b e prepared by courtesy of management and sta of Sonneb erg Ob
servatory
Thomas BERTHOLD
Bundesdeutsche Arb eitsgemeinschaft
f ur Ver anderliche Sterne e V
Bruno H B urgel Sternwarte Hartha
T opelstra e
D Hartha
References
Isles J E Brit Astr Assoc Var Star Section Circ No
Kholop ov P N et al Gen Cat of Var Stars th Ed
Renson P Astron Astrophys
Strohmeier W Astron Nachrichten
Strohmeier W a Ver o Remeis Sternwarte Bamberg V
Strohmeier W b Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
MINIMUM TIMES AND PERIOD BEHAVIOUR OF THE
NEGLECTED ECLIPSING BINARY WZ CYGNI
The variable star WZ Cyg BD is an eclipsing binary exhibiting a Lyrae
type light curve It is a p o orly observed system Ko ch et al and for this reason it
was included in our observational program of and
WZ Cyg was observed photo electrically with the two beam multi mode nebular stellar
photometer attached to the m Cassegrain re ector at the Kryonerion Astronomical
Station of the National Observatory of Athens Greece
Observations were made during nights June and
June July and nights May June
September in
From our observations seven new minima times were derived which are given in Table
where the C s have b een computed using Kholop ov s ephemeris formula
d
MinI J D : E
and are the mean values of our B and V observations
Table
Hel JD Min Filter E O C
Type days
I B V
II B V
II B V
I B V
II B V
I B V
I B V
Moreover from the photographic and photo electric minima times of WZ Cyg found in
the literature Kurzemniece Hanzl and our new ones given in Table the
O C diagram of the system was constructed and is presented in Figure Most of the
minima times presented in this gure are primaries From the data available up to now
b oth primaries and secondaries seem to b ehave in a similar way
Figure The O C diagram of WZ Cyg based on photographic diamonds and photo electric crosses
minima times only The C s have b een calculated according to ephemeris given in the GCVS The
continuous line presents the quadratic least squares tting
As it was p ointed out WZ Cyg is a p o orly observed system and much more data are
needed for a complete study of its orbital p erio d which has b een certainly increasing
Here we only try to t a least squares second order p olynomial and improve Kholop ov s
ephemeris although there are not much data for long p erio ds of time We nd
d
Min I J D : E E
considering the photographic data with the weights given by Kurzemniece Figure
presents the quadratic least squares tting as well
Acknowledgements P H Rovithis are indebted to Dr N Samus who provided
them the copy of the old pap er of Kurzemniece containing valuable data Moreover A
K thanks the Research Com of Athens University for nancial supp ort No
P ROVITHIS
H ROVITHIS LIVANIOU
Astron Institute
A KRANIDIOTIS
National Obs of Athens
Section of Astrophysics
P O Box
Astronomy Mechanics
Athens
Athens University Greece
Greece
GR
Zografos Athens Greece
e mail elivan atlas uoa gr
References
Hanzl D IBVS No
Kholop ov P N General Catalogue of Variable Stars th Edition Moscow
Ko ch R H Woo d F B Florkowski D R Oliver J P IBVS No
Kurzemniece I Trudy Inst Fiz i Mat AN Latv SSR Astronomy vyp
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
NONVARIABILITY AMONG BOOTIS STARS I I
SAAO CTIO AND IAA DATA
This is the second compilation of results which revealed photometric stability within
our extensive survey for pulsation in Bo otis stars The scienti c background of this
program is describ ed by Weiss et al The rst list of constant results was
presented recently in this journal Paunzen et al The photometric results shown
in this pap er are based on four observing runs at three di erent sites obtained by the
observers R Kuschnig RK and M Gelbmann MG The measurements were p erformed
with the cm telescop e of the South African Astrophysical Obs SAAO the cm
Lowell telescop e at Cerro Tololo Inter American Obs CTIO and the cm telescop e
of the Instituto Astro sica Andalucia IAA Table lists all observed con rmed or
candidate see question mark Bo otis and comparison stars with the date and the
duration of the observations The time series analysis was done with a standard Fourier
technique Breger and applied to the di erential photometry The last column
gives the noise level in the amplitude sp ectrum obtained from di erential photometry
the actual comparison star is marked with an asterisk in Table and is hence the upp er
limit of an eventual variability in the frequency range from to c d
Acknowledgement This research was done within the working group Asteroseismology
AMS Computing resources and nancial supp ort for this international collab oration were
provided by the Fonds zur F orderung der wissenschaftlichen Forschung pro ject S
AST and the Ho chschuljubil aumsstiftung der Stadt Wien Bo otis Sterne This re
search has made use of the Simbad database op erated at CDS Strasb ourg France
R KUSCHNIG
M GELBMANN
E PAUNZEN
W W WEISS
Institut f ur Astronomie
T urkenschanzstra e
A Wien Austria
e mail kuschnig astro ast univie ac at
References
Breger M Communications in Asteroseismology
Paunzen E Weiss W W Kuschnig R IBVS No
Weiss W W Paunzen E Kuschnig R Schneider H A A
Table Program and comparison stars
Star Site Observer JD hours m Sp ec Upp er limit v
V
HD SAAO RK Bo o
HD A V
HD F
HD CTIO MG Bo o
HD B
HD SAAO RK Bo o
HD F V
HD F V
HD IAA RK Bo o
HD A V
HD A p
HD CTIO MG Bo o
HD A IV
HD K I I I
HD SAAO RK Bo o
HD A V
HD A V
HD SAAO RK Bo o
HD A V
HD A V
HD IAA RK Bo o
HD A Vn
HD A V
HD SAAO RK Bo o
HD A IV
HD F I I I
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
ON THE PECULIAR FLICKERING ACTIVITY OF HR
Be stars are known to b e variable with p erio ds of the order of one day and with
amplitudes of a few p ercent in light and radial velocity Baade mentions HR
HD CMa as an example displaying prominent short p erio d sp ectroscopic
d d
variations P Asso ciated p erio dic photometric variations with P were
rep orted by Dachs Lemmer and also by Balona et al who obtained a
d
p erio d twice as much viz P
Photometric variability on time scales b etween a few days and several years with typ
m m
ical amplitudes of in uv by are rep orted by Sterken et al Two types
d
of variability are seen viz a quasi regular oscillation with P increasing ampli
tude towards redder wavelengths and a sup erimp osed very long term trend that if it is
p erio dic has a cycle length of the order of several years Moreover random short term
d
variability is added on the oscillation
All measurements of HR discussed here were obtained by one observer in a single
observing run using a stable instrumental con guration Danish cm telescop e at La
Silla in the framework of the Long term photometry of variables pro ject LTPV Sterken
The measurements were obtained di erentially using two nearby comparison stars
see Table for the details Each measurement consisted of one uninterrupted integration
of s simultaneously in the u v b and y bands for the sky background one single s
integration was secured for the program star and for b oth comparison stars sequence
APB The night when the are was observed o ccurred close to full mo on however all
sky background measurements have very consistent values and the deviating p oint can not
readily b e attributed to spurious light coming from the mo on HR has the highest
count rate of the three stars still it displayed the highest internal variance throughout
the whole observing run indicating the presence of steady high frequency variations in
the photon ow that could b e characterised by ickering with very o ccasional aring
It would b e interesting to undertake high sp eed photometric measurements of this star
Figure shows a di erential b y c diagram for HR and three other Be stars in
vestigated by Sterken et al Except for HR the variations in b y and c are
mo derate but not small see the scale in c The variations of b oth indices are huge in
the case of HR with a most interesting single excursion in b y on HJD
m
where the b y index suddenly b ecomes redder This e ect is solely due to a spike
m
that is visible in the y band as a sudden brightening of this jump can also b e seen in
the non di erential data in the instrumental system Figure and is according to the
low mean errors on the successive integrations without any doubt of non instrumental
origin note that evident observational mistakes such as centering errors or observing in
cloudy weather tend to diminish light in all passbands rather than pro duce spikes We
1 BASED ON OBSERVATIONS OBTAINED AT THE EUROPEAN SOUTHERN OBSERVATORY LA SILLA CHILE
Delta c1 -1.1 HD173219 -1.0
-0.9 HR2855 -0.8 y -0.7
-0.6 HR2492
-0.5 b -0.4
-0.3 v -0.2
-0.1 u 0.0
0.1 HR4074
-0.2 -0.1 0.0 0.1 0.2 6380 6400 6420 6440 Delta (b-y)
HJD -2440000
Figure Di erential b y c diagram for HR and three other Be stars indices relatively to their
resp ective comparison stars with similar records of observation left uv by di erential magnitudes of
HR around JD causing the outlying b y data p oint tick marks on the magnitude axis
m
are apart right
cts/s 70000 HR2492
60000
50000 HR2415 40000
30000 HR2497 20000
6415 6420 6425 6430 6435 6440
H JD-2440000
Figure y count rates of HR and comparison stars HR and HR
2E-9 )
2 - m
1 - W
1E-9 m n (
X U L F
400 500 600
wavelength (nm)
Figure K blackbo dy energy distribution for HR Filled circles are from dereddened ubvy
data op en circles represent UBVB B V G photometry see text
nd additional supp ort for our conclusion from an investigation of the amount of variance
seen in the counts of successive second integrations recorded during observations That
variance as a rule is a very go o d indicator of the go o dness of sky quality and should
b e of the same order of magnitude for the comparison stars as for the program star
provided that the sky transparency is stable and that the photon noise is similar for all
stars involved In the case of HR this internal disp ersion amounts to more than twice
the overall mean error obtained from comparison star data covering more than years
Note that the p eculiar measurement on HJD is not listed in Manfroid et al
b ecause it was removed by an automatic ltering pro cedure checking for o ccasional
outliers in the data
The interpretation of the observed phenomenon is not straightforward esp ecially b e
cause the are has b een seen in one passband only One could for example compare the
m m
observed excursion in b y with the strong and abrupt reddening b y
of CMa rep orted by Mennickent et al though that case is di erent since the
are was related to a strong fading An example of an equally unexplainable but opp osite
situation is given by Ventura et al who observed a strong U band are with
asso ciated micro activity in the light output of the dM e star V Oph whereas no
are in V was seen
Using E derived from Geneva colours we dereddened our mean uv by data
B V
Table and the Geneva photometry from Rufener Figure shows the results
together with a blackbo dy energy distribution corresp onding to K Waters et al
There is no sign of the presence of a red companion and unpublished J H K LM
photometry collected by one of us C S con rms that in the near infrared region there
is no excess radiation of the sort exp ected from a co ol companion Waters et al
discussed the infrared excesses at and m of a total of Be stars For stars in
this sample among which HR the infrared excesses can b e completely attributed
to a circumstellar equatorial disk
In spite of the absence of a red companion HR could b e a binary containing
a close compact secondary white dwarf or neutron star This companion should b e
surrounded by a classical accretion disk which always acts as an e ective repro cessor of
energy from short to longer wavelengths Therefore the observed are could b e caused by
a repro cessed X ray burst into optical wavelengths through the pro cedure of absorption
of part of the infalling X rays and consequent heating with emission of most of its energy
b eyond nm the y passband Transient X ray radiation is lib erated whenever
p otential energy is released in an strong accidental accretion event onto the surface of a
compact companion
Table Program P and comparison stars A B average y V b y m c magnitudes and
their overall standard deviations based on the non di erential nightly mean values for each star N
denotes the total number of observations of each star The results are based solely on data b elonging to
System taken during a time interval of more than years Sterken et al see also Sterken
LTPV HR MK y V b y m c N
y b y m c
1 1
P B I I I e
A B V
B B IV
Note that strong wavelength dependence of sp ectral features is not uncommon in sys
tems with accretion disks An extreme example is Lyrae where a disk is present
together with at right angles to it supplementary elongated clouds of ionised material
as inferred Nordsieck et al and indep endently by Harmanec et al In
the Lyrae system the visual and ultraviolet light emissions are shifted in p olarisation
angle consequently disabling detection of are events in di erent passbands
This work was supp orted by a grant from the Belgian Fund for Scienti c Research NFWO
C STERKEN
N VOGT
Faculty of Sciences
Astrophysics Group
University of Brussels VUB
Ponti cia Universidad Cat olicade Chile
Pleinlaan
Casilla Santiago Chile
B Brussels Belgium
R E MENNICKENT
Universidad de Concep ci on
Facultad Cs F sicasy Matem aticas
Departemento de F sica
Casilla Concep ci on Chile
Belgian Fund for Scienti c Research NFWO
Presently at Sternwarte Sonneb erg Sternwarten str D Sonneb erg
Germany
References
Baade D A A
Balona L A Cuyp ers J Marang F A AS
Dachs J Lemmer U Astronomische Gesel lschaft Abstract Series
Harmanec P Morand F Bonneau D et al A A in press
Mennickent R E Vogt N Sterken C A AS
Manfroid J Sterken C Bruch A et al ESO Sc Rep No
Nordsieck K H Fox G K Co de A D et al UV Visible Spectropolarimetry of In
teracting Binaries by WUPPE and University of Wisconsin Pine Blu Observatory
a p oster pap er presented at the AAS Meeting at Pittsburgh USA
Rufener F Catalogue of Stars measured in the Geneva Observatory Photometric
system fourth edition Gen eve
Sterken C in Precision Photometry D Kilkenny E Lastovica J Menzies Eds
South African Astronomical Observatory
Sterken C Vogt N Mennickent R E A A in press
Ventura R Peres G Pagano I Ro don o M A A
Waters L B F M et al A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
OPTICAL OBSERVATIONS OF SN C IN MCG
Sup ernova SN C in MCG was discovered on Feb UT by J
Mueller on a IV N plate obtained by herself and K M Rykoski in the course of
the second Palomar Sky Survey Precise p ositions were measured by Sicoli on UT
Feb and by Balam on UT Feb The o set from the center of the
00 00
galaxy was determined to b e north and west of the galaxy s nucleus Garnavich
et al provided con rmation of SN C from an image obtained by J Luu with
the m telescop e at Mt Hopkins on UT Feb The sup ernova was estimated to
b e V In addition a sp ectrogram of SN C was obtained by D Koranyi
using the m Tillinghast telescop e showing SN C to b e a type Ia sup ernova near
maximum Weak H emission from the host galaxy indicated a redshift of z
Photometric and astrometric observations of SN C were obtained on four nights
using the m Plaskett telescop e and SITe charge coupled device CCD of the Do
minion Astrophysical Observatory All CCD frames were bias subtracted and at elded
Figure Secondary standard stars near MCG
Table Photometric standard stars near MCG
Star V B V
h m s 0 00
A
h m s 0 00
B
h m s 0 00
C
h m s 0 00
D
using median ltered twilight ats in the usual manner using IRAF Lo cal photomet
ric standard stars from the Guide Star Photometric Catalog Lasker et al were
observed at the same airmass as the sup ernova eld The data has b een brought to the
standard system using color transformation co e cients that were determined by observa
tion of the M standard stars of Christian et al
A photometric sequence of secondary standard stars Figure was established in
the eld of MCG and are listed in Table The astrometric p ositions of the
secondary standard stars were calculated from a frame constants solution involving six
Guide Star Catalog GSC stars Jenkner et al The mean error within the
00
p olygon of GSC stars was determined to b e A detailed description of our astrometric
reduction techniques can b e found in Tatum et al
Di erential magnitudes and colors of SN C are listed in Table for four nights
UT Feb March and March The photometry was p erformed using the
00
IRAF PHOT routine with a measuring ap erture of and sky annulus of radius
00
The FWHM of the stars was determined as The comparison and check stars are
lab elled as stars A and B in Table and Figure The standard deviation of all nightly
comparison check star di erential magnitudes was and magnitudes in the
B and V lter images
Sup ernova C is lo cated north of the core of its host galaxy The host galaxy
can b e detected as far as north of the galaxy core Contamination of the sup ernova
observations by the host galaxy has b een minimized by building mo dels of the host galaxy
using elliptical isophotal tting Jedrzejewski as implemented with the IRAF
routines ELLIPSE and BMODEL in the STSDAS package and subtracting the mo del
galaxies from the original images Errors induced by the mo delling pro cess have b een
estimated by placing arti cial SNe in areas of the host galaxy that have similar surface
brightness and gradient to the region containing SN C The mean error induced by
the mo delling pro cess is in the B images and in V images The resultant galaxy
subtracted observations are listed in Table as V and B V
sub sub
Preliminary tting Figure of the V band light curve template of Leibundgut
to the galaxy mo delled observations of Table implies that B maximum o ccurred on
UT Feb JDT when SN C was apparent magnitude V
The author wishes to acknowledge G C L Aikman Dominion Astrophysical Observa
tory for obtaining the UT Mar images of SN C and F D A Hartwick and the
Natural Sciences and Engineering Research Council NSERC of Canada for their supp ort
in this work
1
IRAF is distributed by National Optical Observatories which is op erated by the Asso ciation of Universities for Research in Astronomy Inc under contract to the National Science Foundation
Table Observations of SN C
JDE V B V V B V
S ub S ub
SN 1996C V observations -0.1
0.1
0.3
0.5
0.7
0.9
V - V(max) 1.1
1.3
1.5
1.7
1.9 -1 4 9 14 19 24 29 34
Days from B Maximum
Figure Light curve V of SN C
D D BALAM
Dept of Physics and Astronomy
University of Victoria
Victoria BC CANADA V W P
Internet cosmos uvvm uvic ca
References
Balam D D IAU Circular No
Christian C A Adams M Barnes J V Butcher H Hayes D S Mould J R and
Siegel M PASP
Garnavich P Reiss A and Kirshner R IAU Circular No
Jedrzejewski R I MNRAS
Jenkner H Lasker B M Sturch C R McLean B J Shara M M and Russell J L
AJ
Koranyi D IAU Circular No
Lasker B M Sturch C R Lop ez C Mallama A D McLaughlin S F Russell J L
Wisniewski W Z Gillespie B A Jenkner H Siciliano E D Kenny D Baumert
J H Goldb erg A M Henry G W Kemp er E and Siegel M J Ap J
Suppl
Leibundgut B PhD Thesis Basel
Mueller J IAU Circular No
Sicoli P IAU Circular No
Tatum J B Balam D D and Aikman G C L Planet Space Sci
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
THE PULSATION FREQUENCIES OF CMa
CMa is one of the brightest Cep stars in the sky As such it is a di cult ob ject
to observe without the use of neutral density lters or other techniques of preventing
saturation of the photomultiplier This p erhaps explains why there are no photometric
observations since those of Shobbro ok
CMa is the second brightest ob ject in the sky in the sp ectral range A the
brightest b eing CMa Observations of CMa in the EUV are presented by Cassinelli
et al results of observations of CMa in the EUV by the same group are in
press It turns out that there are several anomalies regarding the continuum of CMa
at these short wavelengths It is p ossible that this may have something to do with the
re distribution of pulsational energy The link b etween the EUV excess and pulsation
is b eing studied further by Cassinelli and co workers Since the EUV and the optical
p ortions of the sp ectrum form at di erent heights in the atmosphere it is imp ortant to
obtain contemporaneous optical photometry for the star
Str omgren uv by photometry of CMa was obtained in January using the
m re ector of the SAAO A total of data p oints in all four colours was obtained
A mag neutral density lter was employed As comparison stars we used the nearby
B type stars HR and HR These were observed without neutral density lters
to maximise the signal The ND lter was calibrated by observing one of these stars
with and without the lter through each of the four bands In addition we included in
the analysis uv by measurements made with the same telescop e and equipment in
November The same comparison stars were used
A p erio dogram of the data shows the main pulsation at f cycles d
having a semi amplitude of mmag There is no sign of additional p erio ds in
our data with semi amplitudes in excess of mmag The results for the data
are the same there is a strong p eak in the p erio dogram at f d but nothing
further with a semi amplitude in excess of mmag The p erio dograms of the b data for
the two seasons are shown in Fig Shobbro ok obtains the following frequencies
and semi amplitudes f A f A f
A cycles d and mmag resp ectively The time span within our two
separate runs is to o short to resolve f and f but is su cient to resolve f Evidently
our observations are of to o short a duration to reduce the noise level to a p oint where f
and f b ecome visible
The frequency of f determined by Shobbro ok ts the combined data from
and very well if the frequency is revised slightly to f d We obtain the
following ephemeris for maximum light in all four colours there is no appreciable phase
d
shift b etween any two colours T JD E The following
max
semi amplitudes are obtained in mmag A A A
y b v
A There is a very large increase in amplitude in the u band but at the u
Table Str omgrenphotometry of CMa
HJD V b v u HJD V b v u
Table continued
HJD V b v u HJD V b v u
Figure Periodograms of the b data for CMa Left panel the data right panel
the data The frequency is in cycles d and the amplitude in mmag
same time the photometric accuracy is much worse owing to the p o or prop erties of the
ND lter
One can also adopt the three p erio ds as known comp onents and attempt to t the
combined and data with these p erio ds In that case we nd semi amplitudes of
mmag for f and f in the y b and v bands However the amplitude of f increases
to mmag in u and is in fact larger than f mmag Because f and f are not
resolved in either of the two seasons we view this result with suspicion It is p ossible
that the large rise in amplitude of f in the u band may not b e entirely real but could
b e aided by an even steep er rise in the unresolved comp onent f It is interesting to note
that while f has a much larger amplitude than f in optical photometry the two have
comparable radial velocity amplitudes Kubiak
L A BALONA
L BREGMAN B A LETSAPA
B T MAGORO S E WALSH
South African Astronomical Observatory P O Box Observatory
Cap e Town South Africa e mail lab saao ac za
SAAO Summer School Student
References
Shobbro ok R R MNRAS
Cassinelli et al ApJ
Kubiak M Acta Astr
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
March
HU ISSN
MULTIPERIODICITY IN PULSATING LAMBDA Bo o STAR
Cyg HD V Cyg
The rst and rm detection of pulsation phenomena in Bo o type stars was made
for classical Bo o star Cyg by Gies Percy Gies Percy G P
rep orted ab out the min variability of Cyg with an amplitude of ab out mag
They suggested that in contrary to Am and Ap stars lying in the Scuti instability strip
the mo derate amplitude pulsations cannot b e an exclusion in Bo o group Until the
early ies few attempts were carried out for investigation of pulsational activity of this
group of stars or the attempts were made for nonclassi ed members of this group as for
susp ected Sct type stars At present up to pulsating members are known Kuschnig
et al
The new observations of Cyg were obtained during eight nights of July September
within the frames of collab orative program of the Odessa Astronomical Observatory
Ukraine the Sternberg State Astronomical Institute Russia and Tien Shan High Al
titude Observatory Kazakhstan for the search and investigation of pulsating northern
chemically p eculiar and Scuti type stars We used a channel W B V R photometer
Kornilov Krylov attached to the m telescop e of the Tien Shan High Altitude
Observatory The integration time was seconds simultaneously in the four lters and
the data were binned in second time intervals prior to the analysis The comparison
m
stars HD G I I I V and HD A V V : were used
This brief note represents the p erio dicity analysis of B R index data less a ected by
the in uence of the marginal weather conditions the atmospheric scintillation noise and
extinction variations This technique is based on the fact that the atmospheric scintillation
noise is strongly coherent in di erent wavelength bands and amplitudes of variability are
maximal in the blue region of sp ectra of A stars and decrease at the long wavelengths
Figure shows the resulting instrumental B R data for JD JD
JD JD JD JD JD and JD reduced
to the mean level The analysis of separate nights shows that the main p erio dicity at the
frequency near c d is present in the B R data
The amplitude sp ectra of B R data combined for nights of photometry are given in
Figure The highest p eak with semi amplitude of ab out mmag is present at frequency
c d min After the application of consecutive prewhitening pro cedure and
frequency analysis we have resolved up to frequencies The amplitudes of frequencies
are slightly variable from night to night The frequencies f and f can b e the artifacts
pro duced by the variability of main frequencies and c d Frequencies am
plitudes and phases were corrected by the application of the simultaneous frequency
iterative sine wave least squares tting pro cedure
The resulting frequencies and amplitudes are given in Table The frequency syn
thetic curve is shown in Figure by the solid line
Table Frequency t for JD B R and G P V data sets
B R data Present pap er V data Gies Percy
Freq c d Semi ampl mag Freq c d Semi ampl mag
f f
f f
f f
f f
f f
f
f
Figure The B R light curves for Cyg The solid line is the frequency t see Table
Figure The amplitude sp ectra of B R data shown in Figure
In order to con rm the frequencies detected we re analysed the Gies and Percy s
year data set Gies and Percy Our analysis of the G P V lter data after removing
the trends pro duced by the c d variability of comparison Be star Cyg Pavlovski et
al gives the frequency solution also presented in Table The comparison of two
solutions shows that at least frequencies in our data set are close to those presented in
G P data In contrary to our year observation the maximal amplitude of variability
of G P data set is at frequency of c d min For G P data set the amplitude
ratio for the mean amplitudes of two frequencies and c d is equal to For
our data set this ratio is equal to i e this result is a con rmation of amplitude
variability of excited mo des in Cyg and this fact of amplitude variability is not an
exclusion for stars which o ccupy the blue edge of instability strip see the extreme case
of mo de variability in HD A V in pap er of Kusakin Goranskij
The main results of our brief note are as follow
Cyg is a pulsating Bo o star with a multiperio dic structure of excited mo des the
two highest amplitude excited mo des have the frequencies near and cycles
p er day
We con rm at least of detected frequencies by the re analysis of nights of Gies
Percy V data for Cyg
The amplitudes of the excited mo des are variable
A V KUSAKIN
Sternberg State Astronomical
Institute Universitetsky prosp ect
Moscow Russia
D E MKRTICHIAN
Astronomical Observatory
Odessa State University
Shevchenko Park Odessa
Ukraine
e mail david oao odessa ua
References
Gies D R and Percy J R AJ
Kornilov V G and Krylov A V Russian Astron J
Kusakin A V and Goranskij V P Russian Astron J in press
Kuschnig R Paunzen E and Weiss W W IBVS No
Pavlovski K Ruzic Z and Vujnovic V Inside the Stars eds Weiss W W and
Baglin A IAU Collo quium ASP Conference Series p
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NEW DEEP MINIMUM OF THE CATACLYSMIC BINARY KR Aur
IN
KR Aur whose variability was discovered by Popova is a member of the nova
like sub class known as anti dwarf novae Its sp ectroscopic observations revealed that it
is a close binary system consisting of a white dwarf M and a red dwarf M
with orbital p erio d of hours and inclination angle smaller than degrees Shafter
m m
The brigthness of KR Aur is usually b etween predominant value :
m m
with o ccasional decreases to : but it drops to episo dically Rapid variations with
m
amplitude up to : and time scales seconds and minutes ickering are typical for the
star in its bright state The last deep minimum was observed in when the star
m
dropp ed to approximately Popov Popova et al
We present photometric and sp ectral observations of KR Aur in the p erio d September
November
The photometric observations were carried out through B lter using cm Cassegrain
telescop es with identical one channel photo electric photometers at the National Astro
nomical Observatory Rozhen NAO and at the Astronomical Observatory Belograd
chik AOB and the cm Schmidt telescop e at NAO with ZU plates and B lter
The integration time was seconds and the exp osure time was minutes for all ob
servations resp ectively The magnitudes of the variable were estimated on the basis of
m
the standards published by Popova The accuracy was : for the photo electric
m
observations and : for the photographic ones U monitoring for ickering search was
carried out for nights The observational data are presented in Table and Figure
One sp ectrum with A resolution was obtained on February in the region
A Figure The m telescop e of the Sp ecial Astrophysical Observatory of
the Russian Academy of Sciences with channel TV scanner was used Afanas ev et
al The data pro cessing was done by means of the package ETAM Knyazev
Lip ovetskii
Our observations revealed that KR Aur underwent a minimum again We think a pre
drop state of the star has app eared since January The star displayed an unstable
m m
brightness from : in December to : on January Antov Popov
m
On January KR Aur was fainter than In all observations up to January
ickering was present however on January it seems to b e absent The
last measurement is a little bit uncertain b ecause the ob ject was to o faint then
An interesting fact is that in the b eginning of February KR Aur increased its
m
average value and our estimates showed fast brightness to maximum light again :
m
changes in B light up to : amplitude Our measurements in this p erio d are in an
agreement with the visual estimates of Verdenet Mizner
Table
Date H J D m Obs Telescope Flickering
B
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain Yes
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain Yes
NAO Cassegrain Yes
NAO Cassegrain No
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
NAO Cassegrain
AOB Cassegrain
AOB Cassegrain No
AOB Cassegrain No
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain
AOB Cassegrain No
NAO Cassegrain
NAO Schmidt
NAO Schmidt
NAO Schmidt
NAO Schmidt
NAO Schmidt
AOB Cassegrain Yes
Figure The photometric b ehaviour of KR Aur Y denotes presence of ickering with amplitude
m
: N absence of it
Figure The sp ectrum of KR Aur obtained on February with the m telescop e of the Sp ecial
Astrophysical Observatory
m
In a month the star dropp ed again to : Its sp ectrum obtained on February
is closer in time to the maximum light state and resembles those observed with
the same equipment by Popov Kraitcheva The detected Balmer emission lines
H H H and H have a two component structure with a redward shifted second
comp onent In so far as these lines are considered to originate from the accretion disk
material Shafter we suggest that the disk still exists in the system
m m
In the p erio d March Octob er KR Aur varied in the interval : :
The star has b egun to decrease its brightness since Octob er and approximately in
m
months March reached : which is in an agreement with the observations of
Honeycutt Rob ertson
The deep minimum state lasted approximately months The faintest magnitude of
m
the star detected on Octob er was However this measurement is uncertain
b ecause the ob ject was near the plate limit From Octob er to November
m m
KR Aur b ecame brighter and a ickering with an amplitude of : in U lter
was detected again on November
We think that the star had an unusually unstable mass transfer in a p erio d months
b efore its fading to a deep minimum It is p ossible that a pre minimum state exists for
KR Aur A slow decrease of the mass transfer followed and it seems the ob ject sp ent
a long time in an intermediate state KR Aur faded from its intermediate state to the
minimum for months It sp ent months in minimum state The star went out of the
minimum relatively quickly for a little more than a month
The authors are thankful to Dr I Pan orova for pro cessing the sp ectral material
This work is partially supp orted by the Bulgarian National Science Foundation under
contract F
A P ANTOV
R KONSTANTINOVA ANTOVA
E SEMKOV
N BORISSOV
Tsv GEORGIEV
V UMLENSKI
Institute of Astronomy Bulgarian Academy of Sciences
Tsarigradsko shosse blvd BG So a Bulgaria
e mail b elogr bgearn acad bg
Sp ecial Astrophysical Observatory of the Russian Academy of Sciences
Niznij Arhyz Karachaevo Cherkezia
References
Afanas ev V L Lip ovetskii V A Mihailov V P et al Astrophys Invest Izv
SAO
Antov A P Popov V N IAU Circ No
Honeycutt K Rob ertson J IAU Circ No
Knyazev A Yu Lip ovetskii V A Otchet SAO No
Popov V N IBVS No
Popov V N Kraitcheva Z T Contributions of the Astronomical Observatory
Skalnate Pleso
Popova M D Mitt Ver and Sterne Sonneberg No
Popova M D Peremennie Zvezdi
Popova M D Antov A P Popov V N in Magnetic and Variable Stars Com
mun Konkoly Obs Hung Acad Sci Budap est eds M Marik and L Szabados
No p
Shafter A W ApJ
Verdenet M Mizner M IAU Circ No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
ROTATION PERIODS FOR FOUR LOW MASS STARS IN THE
TAURUS AURIGA REGION WITH Ca I I EMISSION
We present the results of a long term photometric monitoring campaign for four stars
in the Taurus Auriga region that were found to have strong Ca I I H and K emission by
Herbig et al The BVR observations were obtained during four runs from August
to December at the Mt Maidanak Observatory Uzb ekistan using a
m telescop e equipp ed with a pulse counting FEU photomultiplier tub e The mean
m
error of one observation of a program star is typically in V B V and V R
The interval of observations number of observations in V and B V limits of the light
variations in V lter mean magnitude and colours are listed in Table Maidanak BVR
photometry Data Bank is at Tashkent Astronomical Institute and available to anyone
interested in
Anon LkCa
q q
q q
q q
q q
q q
q q
q q
q q q q
q q
q q
q q q q
q q
q q
q q
q q
q q
q q
q q q q
q q q q
q q
q q q q q q
q q
q q q q
q q
q q q q
q q
q q q q
q q
q q
q q
q q
q q
q q
q q q q q q
q q
q q
q q
q q
q q
q q q q
q q
q q q q q q
q q
q q q q
q q q q
q q q q
q q
q q
V
q q q q q q q q
q q
q q
q q
q q
q q q q
q q
q q q q
q q q q
q q q q
q q q q
q q
q q q q
q q q q
q q q q q q
q q
q q
q q q q
q q
q q
q q
q q
q q
q q
q q
q q
q q
q q
q q q q
q q
q q q q
q q
q q
q q
q q
q q q q
q q
q q
q q
q q
LkCa LkCa
q q
q q
q q q q
q q
q q
q q
q q
q q
q q q q q q
q q
q q
q q
V
q q q q
q q
q q
q q q q
q q
q q
q q q q
q q
q q
q q q q
q q
q q
q q
q q
q q
q q q q
q q
q q q q
q q
q q
q q
q q
q q
q q q q
q q
q q
q q
q q
Phase Phase
Figure Phase diagrams for light curves in the V lter for stars
We rep ort rst detections of p erio dic light variations for Anon LkCa LkCa and
LkCa A p erio dogram analysis reveals that all the Ca I I stars have signi cant p eaks
in their p ower sp ectra The most probable p erio ds of these stars and their ep o ch of
observations are listed in Table Phase diagrams for light curve in the V lter for four
stars are displayed in Figure
Table
Name Obs n V V
max min
Interval day observ
Anon
LkCa
LkCa
LkCa
n number of observations in V and B V
n number of observations in V R
d d d
two p erio ds and can b e present which pro duce fully equivalent folded light curves with P
d
another p erio d pro duces fully equivalent folded light curve with P day
It should b e noted that there are several other signi cant p eaks in the p ower sp ectra
for LkCa and LkCa The p erio ds which corresp ond to these p eaks are listed in the
notes to Table The spacing of the observations in time one day causes false p erio ds
These p erio ds can b e calculated from the equation j j day where
P P
f
P is true p erio d P are false p erio ds One of the p erio ds is true the others
f
are false p erio ds Both true and false p erio ds pro duce fully equivalent folded light
curves In order to choose true p erio d it is necessary to carry out further monitorings
with observations more frequent than once a night
The p erio dic variability of these ob jects can b e interpreted as the rotational mo dulation
of the stellar ux by a group of dark surface sp ots These four Ca I I stars together with
d d d d d
LkCa LkCa LkCa LkCa LkCa LkCa
d d
and LkCa monitored by Grankin Vrba et al
and Bouvier et al form a sample of eleven ob jects from Herbig et al s list
with known rotational p erio ds Thus there is a high detection rate of rotational p erio ds
amongst Ca I I stars in the sample considered It should b e noted that Anon LkCa
LkCa and LkCa keep their rotational p erio ds in intervals from to years see
also Grankin The stability of rotational p erio ds over several years indicates that
the active region in each Ca I I star remains on a de nite meridian over this time scale
Prop erties of the active regions for these stars are similar to those of RS CVn stars
Konstantin N GRANKIN
Astronomical Institute
Astronomical str Tashkent
Uzb ekistan
e mail grankin silk glas ap c org
References
Bouvier J et al Astron Astrophys
Bouvier J et al Astron Astrophys
Grankin K N IBVS No
Grankin K N IBVS No
Grankin K N IBVS No
Herbig G H et al Astron J
Vrba F J et al Astron J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
PHOTOMETRIC OBSERVATIONS OF THE NEW BRIGHT CLASSICAL
CEPHEID SAO HD
The star SAO HD BD PPM AGK GSC
of sp ectral type G is one of the variables discovered by the TYCHO Instru
ment of the ESA Hipparcos Satellite It was announced to have a magnitude variation
range b etween and in T magnitudes TYCHO magnitudes with a p ossible
day p erio d Makarov et al As a result of an observational program prop osed by
Bastian Born observed visually the star indicating that it should b e a new
delta Cephei star with a day p erio d
Without previous knowledge of the work by Born we pro ceeded from Octob er
to visually monitor SAO Initial observations indicated that the p erio d of the light
variation was much shorter than the announced value of days For this reason we
decided to continue our monitoring work photometrically Due to the fact that we had
to deal with a rather bright star and also the need to work with a wide eld to include
suitable comparison stars in terms of brightness and color index from December to
February we underto ok the task of observing SAO in the V band at Piera
Observatory Spain using a cm nder telescop e and a LYNXX CCD camera We
chose SAO HD BD PPM GSC as a comparison
star Figure
At the same time we to ok some brightness measurements using the m telescop e
at Mollet Observatory Spain and an Optec SSP photometer We also determined the
V and B magnitudes of the comparison star SAO using HR HR and
HR as reference stars
Our observations allowed us to conclude that SAO is a bright cepheid V
magnitudes at maximum light with a p erio d close to days and an asymmetry
factor M m P with a variation range of magnitudes in the V
band Figure According to light curve shap e SAO can b e classi ed as a classical
cepheid Nevertheless this last statement should b e con rmed by other observational
means
We derived the following ephemeris
d
Max HJD : E
Photographic archival plates stored at various observatories should b e analysed to
re ne the ab ove given ephemeris as well as reconstruct the past years light curve of this
new cepheid
Francisco CAMPOS CUCARELLA Enrique GARCIA MELENDO
Joan GUARRO FLO Esteve Duran Observatory
Josep M GOMEZ FORRELLAD El Montanya Seva
Grup d Estudis Astronomics SEVA
Apartado Barcelona
Barcelona Spain
Spain e mail duranobs astro gea cesca es
e mail jmgomez astro gea cesca es
References
Bastian U Sterne und Weltraum No
Born E BAV Rundbrief No
Makarov V Bastian U Ho eg E Grossmann V and Wicenec A IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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April
HU ISSN
NEW PHOTOMETRIC DATA FOR HD AND HD
We present new photometric data for HD and HD two Bo otis stars
which were found to b e variable in former publications The Bo otis stars are a group
of metal p o or p opulation I A type stars Weiss et al
HD m was found to b e variable in Paunzen Weiss with
V
a p erio d of minutes and an amplitude of mmag in Str omgren v and b Additional
observations were published in Paunzen et al They result in a p erio d of
minutes and an amplitude of mmag in Str omgren v and b At this stage we were only
able to con rm variability in HD but could not decide b etween the two prop osed
p erio ds Therefore we reobserved HD to determine its p erio d and amplitude
The observations were made in the night of May by E Paunzen with the
meter Lowell telescop e at CTIO with an integration time of seconds in Str omgren
v and b HD m F V was used as comparison star The lightcurves of
V
b oth stars are shown in Figure The result of a Fourier analysis p erio d minutes
amplitude b mmag seems to con rm the results of
HD Cygni HR m is one of the classical and b est studied
V
Bo otis type stars Its p eculiarity was discovered by Slettebak Abundance analysis
of this star Venn Lambert and St urenburg gave a metal de ciency of ab out
a factor of compared to the Sun
Pulsation was rst rep orted by Gies Percy They analysed nights of pho
tometry and determined a multiperio dic variation of ab out minutes with an amplitude
of ab out to mmag in Johnson V They used Cygni as comparison star Cygni
is known as a variable Be star Its frequency pattern is quite complicated and the p erio ds
range from to hours Peters Penrod and Bossi et al Therefore we
reobserved HD to con rm its variability
The observations were made in the nights of and Aug by G Handler
at the meter telescop e of the McDonald Observatory with an integration time of
seconds in Str omgren v and b We have chosen HD HR m A V and
V
HD HR m B I I I as comparison stars The second one turned out to
V
b e variable Figure shows extinction corrected instrumental magnitudes for the second
night and indicates multiperio dic variations for HD The amplitude sp ectrum for
the merged data indicates two p erio ds of and minutes with an amplitude of ab out
and mmag in Str omgren b This result is consistent with Gies Percy
We encourage further observations of HD and HD to apply the to ols of asteroseismology
HD 142703 0.02 mag(b)
HD 142640
0.65 0.70 0.75 0.80 0.85
JD 2449840+
Figure Lightcurves for HD and HD in Str omgren b
HD 192640 0.06 mag(b)
HD 195050
0.7 0.8 0.9
JD 2449940+
Figure Lightcurves for HD and HD in Str omgren b for the second night
Acknowledgement This research was done within the working group Asteroseismology
AMS Computing resources and nancial supp ort for this international collab oration were
provided by the Fonds zur F orderung der wissenschaftlichen Forschung pro ject S
AST and the Ho chschuljubil aumsstiftung der Stadt Wien Bo otis Sterne GH ac
knowledges partial nancial supp ort by the Austrian Zentrum f ur Auslandsstudien This
research has made use of the Simbad database op erated at CDS Strasb ourg France
E PAUNZEN
G HANDLER
Institut f ur Astronomie
T urkenschanzstra e
A Wien Austria
e mail paunzen astro ast univie ac at
e mail handler astro ast univie ac at
References
Bossi M Guerrero G Zanin F A A
Gies D R Percy J R AJ
Paunzen E Weiss W W IBVS No
Paunzen E Heiter U Weiss W W IBVS No
Peters G J Penrod G D in A Decade of UV Astronomy with the IUE satellite
ESA SP Vol
Slettebak A ApJ
St urenburg S A A
Venn K A Lambert D L ApJ
Weiss W W Paunzen E Kuschnig R Schneider H A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NSV AND RX J
NSV Sagittae was discovered by Baade as a variable star of
m m
unknown type in the range : : The NSV catalogue Kukarkin et al lists
type E for this ob ject The source of this information is unknown however we could not
nd any other publication on NSV than the one of Baade So the statement
E may b e a private communication or p ossibly a misprint
Unfortunately no nding chart was given and the published co ordinates transform to
h m s 0 00
R A : Dec
00
equinox This is ab out north of the eastern star of the unresolved pair
m
denoted with v in Figure This unresolved pair has a brightness of B on the
m
blue sensitive Sonneb erg plates and R : B R on the POSS plate E taken
in Neither B nor R magnitudes given here are international values they rather
mean blue and red sensitive photographic magnitudes
We checked archival plates of the mm and mm Sonneb erg
m m
astrographs limiting magnitude and plates of the astrograph
for variability of NSV Though di cult to investigate b ecause of its faintness this
m m
star pair seems to b e slightly variable b etween ab out : and B band during the
time span Occasionally we nd indications of at waves days of small
amplitude < mag We do not nd eclipses but given the typical exp osure times of
min eclipses might easily b e undetectable in our data if they are of short duration
and or of small amplitude Though we did not observe any typical are the red colour
indicates the p ossibility that Baade observed a are up of NSV
We got interested in NSV due to the nearby X ray source RX J
discovered during the ROSAT all sky survey This X ray source with b est t co ordinates
h m s 0 00
R A : Dec
00
error of was found at a countrate of cts s The hardness ratios
HR N N N N where N denotes the
a b
number of counts in ROSAT s p osition sensitive prop ortional counter b etween channel a
and channel b and HR N N N though admittedly
purely constrained due to the low number of counts are consistent with coronal emission
from a late type star Thus the brightest ob ject inside the X ray error circle see Fig
m h m s 0 00
with B and lo cated at R A : Dec is a viable counterpart
candidate nearly indep endent of its sp ectral type Only sp ectral types later than ab out
M are less probable due to their implied low X ray to optical ux ratio and their intrinsic
m
colours b eing redder than the B R of this B star
m
A check of this B star on the same plate material as describ ed ab ove revealed no
m
hint for any kind of variability This makes a p ossible mis identi cation of this B
star with NSV rather unlikely
Mo, 25 Mar 1996 11:30:53 MIDAS version: 95NOV 208 39 39 208
Frame : nsv12597 Identifier : nsv ITT-table : ramp.itt Coordinates : 39, 39 : 208, 208 Pixels : 1, 1 : 512, 512 Cut values : 2500, 12000
User : jcg
Figure A nding chart showing the p osition of NSV on the E band Palomar Observatory Sky
Survey plate v marks the pair of stars the eastern of which is thought to b e NSV The circle
00
marks the error radius around the X ray p osition cross of RX J
00
NSV is ab out o the p osition of RX J With the present knowl
m
edge we think that NSV is unrelated to this X ray source and that the B star
m
is the optical counterpart of RX J Sp ectroscopic observations of this B
star in the X ray error b ox as well as of NSV are needed to prove our conclusions
and to determine the type of NSV
Acknowledgements JG is supp orted by the Deutsche Agentur f ur Raumfahrtangele
genheiten DARA GmbH under contract FKZ OR and GAR by the Deutsches
Elektronen Synchrotron DESY PH under contract FKZ S The ROSAT pro ject
is supp orted by the German Bundesministerium f urBildung Wissenschaft und Forschung
BMBW DARA and the Max Planck Society The nding chart Figure is based on
photographic data of the National Geographic So ciety Palomar Observatory Sky Survey
NGS POSS obtained using the Oschin Telescope on Palomar Mountain The NGS POSS
was funded by a grant from the National Geographic So ciety to the California Institute
of Technology The Digitized Sky Survey was pro duced at the Space Telescope Science
Institute under US Government grant NAG W
Gerold A RICHTER Jo chen GREINER
Th uringer Landessternwarte Tautenburg MPI f ur Extraterrestrische Physik
Tautenburg Germany Giessenbachstr
and Garching Germany
Sternwarte Sonneb erg
Sonneb erg Germany
References
Baade W Astron Nachr
Kukarkin B V et al New Catalogue of Susp ected Variable Stars Nauka Moscow
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NEW INFORMATION ON V Cas TYPE AND PERIOD
New photo electric measurements show that V Cas is likely an EB type eclipsing
binary varying from magnitude V to V with a p erio d of approximately
days The variability of V Cas HD was discovered by Strohmeier et al
using the photographic plates from Bamberg The star was mentioned as an eclipsing star
m
of magnitude p with an amplitude of : and A type sp ectrum In and
at the Lund observatory Bern et al measured the star photo electrically They
m m
catalogued it ranging from : to : in V with B V colour index of and U B
colour index of They simply con rmed the variability of the star In the GCVS
Kholop ov et al V Cas is listed as an eclipsing star E varying from to
B with an A to F sp ectrum
new photo electric measurements of V Cas see Table were obtained during
several GEOS missions at the Jungfraujo ch station with the photometer equipp ed with
lters of the Geneva system attached to the cm telescop e These measurements were
carried out from December to August These data con rm the results published
by Bern et al the star varies from to in V with almost constant B V
colour index of
Period search was p erformed using four di erent metho ds The theta statistic function
of Renson gave the b est results due to the limited set of measurements the low
amplitude and the shap e of the light curve
For the light curve Figure the ep o ch was chosen close to the instant of dimmest
magnitude and adjusted using a spline function
Min I HJD E
Figure Folded light curve with measurements in V of V Cas
Table New photo electric measurements of V Cas
HJD V B V
G
with primary minimum at V and secondary one at V the shap e of the light
curve lo oks like the EB type
Jacqueline VANDENBROERE
GEOS Group e Europ een
d Observations Stellaires
Promenade V en ezia
F Versailles France
References
Bern K and Virdefors B Astron Astrophys Suppl S
Renson P Astron Astrophys
Strohmeier W Knigge R and Ott H Ver o der Remeis Sternwarte Bamberg
V Kholop ov P N et al General Catalogue of Variable Stars Fourth edition Moscow
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
ACCURATE POSITIONS OF VARIABLE STARS
NEAR THE SOUTH GALACTIC POLE
Positions for variable stars lo cated around the South Galactic Pole were obtained
by measuring the rst ep o ch plates of the Yale San Juan Southern Prop er Motion Survey
00
The average error of the new p ositions is : in R A and Dec as referenced to the system
of the SRS
This pro ject is a continuation of a program started by Lop ez and Girard The
authors under the guidance of Girard and following the pro cedures developed by Lop ez
and Girard have measured variables and susp ected variables in a region around the South
h h
Galactic Pole SGP The region centered on a R A of extends approximately on
either side The declination extends approximately from to The derived p o
sitions of the susp ected variables in this region will b e presented in a subsequent bulletin
In a conversation with Dr Ho eit it was suggested that the bright stars without a
nder chart could b e lo cated relative to the eld stars on the Cordoba Atlas Using a
cuto magnitude of along with the published p osition and the references as printed in
the GCVS IV Kholop ov et al a b a the stars were lo cated on the CoD
charts Six variable stars were lo cated in this manner and are indicated in the table by
the letter p under comments
Three variables need further study due to the fact that their nding charts and pub
lished p ositions GCVS left a few questions The published p osition for AO Aquarii
caused the survey machine to center on a star that was lab eled b on the nder chart
Tsessevitch One of the authors Predom found another chart by Shapley
and Swope that did identify this star as AO Aquarii The chart by Shapley and
Swope was used for determining the p osition for this variable DS Aquarii had a problem
similar to AO Aquarii but no charts were found to decide which star was the comparison
star and which was the variable Wahlgren also called for further study of this
star to clarify the inconsistency b etween the published p osition and the nding chart
The authors have supplied b oth p ositions and lab eled them DS Aqr until further study
indicates which star is the variable The chart of VW Gru did not show the variable as a
double star however the plate image showed two blended images The published p osition
in this pap er is for the center of mass for this plate image
The results listed in Table are organized by constellation and contain the following
information Variable name newly determined R A and Dec Equinox B with
ep o chs in the range of to the di erences b etween our new p ositions B
and those quoted in the GCVS IV in minutes of time in right ascension and arc minutes
in declination and comments
Table Positions of Variable Stars
Variable Comments
0 00 0
h m s m
S Aqr
X Aqr
RT Aqr CoD
SZ Aqr
WX Aqr
AF Aqr
AG Aqr
AH Aqr
AI Aqr
AK Aqr
AL Aqr
AM Aqr
AN Aqr
AO Aqr see text
AP Aqr
AQ Aqr
AR Aqr
AS Aqr
AU Aqr
AW Aqr
AX Aqr
AY Aqr
AZ Aqr
BB Aqr
BC Aqr
BD Aqr
BE Aqr
BF Aqr
BG Aqr
BH Aqr
BI Aqr
BV Aqr
DN Aqr
DS Aqr see text
DS Aqr see text
DX Aqr
EE Aqr
ER Aqr CoD
ES Aqr CoD
ET Aqr BD
FI Aqr CoD
FK Aqr
FL Aqr NSV
T Cet
RT Cet
SV Cet
TW Cet p CPD
UU Cet
UV Cet
VW Cet
Table continued
Variable Comments
0 00 0
h m s m
VY Cet BD
YY Cet BD
YZ Cet
AA Cet p CoD
AC Cet BD
AE Cet BD
AF Cet CoD
AH Cet BD
AL Cet BD
AU Cet BD
AX Cet
BB Cet BD
SS For
SV For CoD
TT For
R Gru
T Gru
V Gru CoD
W Gru
Y Gru p CoD
RT Gru
RU Gru CoD
RV Gru CoD
RW Gru
RX Gru
RY Gru CoD
RZ Gru
ST Gru
SU Gru
SV Gru NSV
SW Gru
SX Gru
SY Gru
SZ Gru
TV Gru
TW Gru
TX Gru
TY Gru
UV Gru
UX Gru
UY Gru
UZ Gru
VW Gru see text
VY Gru
WW Gru
WX Gru
WY Gru
WZ Gru
XZ Gru CoD
ZZ Gru
Table continued
Variable Comments
0 00 0
h m s m
AA Gru
AB Gru
AD Gru
AE Gru
AF Gru
AG Gru
AI Gru
AK Gru
AM Gru
AN Gru
AQ Gru
AR Gru
AS Gru CoD
AU Gru
AZ Gru
BB Gru
BE Gru
BI Gru NSV
BK Gru CoD
BN Gru NSV
BO Gru NSV
PI Gru
T Phe
V Phe
RR Phe
RU Phe
RV Phe
RW Phe
SW Phe
SX Phe
SY Phe CoD
SZ Phe
TV Phe
TW Phe
TX Phe
TY Phe
TZ Phe
UU Phe
UV Phe
UX Phe
UY Phe
UZ Phe
VV Phe
VW Phe
VX Phe
VY Phe
VZ Phe
WW Phe
WX Phe
WY Phe
Table continued
Variable Comments
0 00 0
h m s m
WZ Phe
XX Phe
XY Phe
XZ Phe
YY Phe
YZ Phe
ZZ Phe
AA Phe
AC Phe
AD Phe
AG Phe
AI Phe
AK Phe CoD
AL Phe CoD
AM Phe CoD
AN Phe
AO Phe
AP Phe
AQ Phe
AR Phe
AS Phe
AT Phe
AU Phe
AV Phe
AW Phe CoD
AX Phe
AY Phe CoD
AZ Phe CoD
R PsA
S PsA
U PsA
V PsA p CoD
W PsA CoD
X PsA
Y PsA
Z PsA
RR PsA
RS PsA
RT PsA
RU PsA
RW PsA CoD
RX PsA
RZ PsA
SS PsA CoD
ST PsA
SU PsA
SW PsA
SZ PsA
TT PsA
TU PsA CoD
Table continued
Variable Comments
0 00 0
h m s m
TV PsA CoD
TW PsA CoD
TX PsA
R Scl
S Scl
T Scl
U Scl
V Scl
W Scl p CoD
X Scl
Y Scl CoD
Z Scl
RR Scl
RT Scl CoD
RU Scl
RV Scl
RX Scl
RY Scl
RZ Scl
SS Scl
ST Scl
SU Scl
SV Scl
SW Scl
SZ Scl
TU Scl
TV Scl
TW Scl
UV Scl
UW Scl
UY Scl
UZ Scl
VV Scl CoD
VW Scl
VX Scl NSV
VY Scl
VZ Scl
WW Scl
WX Scl
WY Scl
WZ Scl CoD
XX Scl CoD
XY Scl CoD
XZ Scl
YY Scl CoD
YZ Scl CoD
ZZ Scl CoD
AA Scl CoD
AB Scl CoD
AC Scl CoD
Table continued
Variable Comments
0 00 0
h m s m
AD Scl
AE Scl
AF Scl CoD
AG Scl CoD
AH Scl CoD
AI Scl CoD
AK Scl
AL Scl p CoD
AM Scl
AN Scl CoD
AO Scl
We would like to thank Dr Terry Girard for his input and guidance Dr Dorrit Ho eit for many
helpful comments and suggestions on the pro ject Dr Imants Platais for his help in translating Russian
text and lo cating some of the nder charts Carlos Lop ez for his initial training and guidance and esp ecially
Dr William van Altena for allowing amateurs a chance to take part in a pro ject of this magnitude
Sp ecial thanks to Michael Dzubaty for helping out in the b eginning stages of the pro ject
This research has b een supp orted in part by NSF grants to Yale Southern Observatory Inc and
Yale University
Rob ert DEMARTINO
Dennis KOCYLA
Christopher PREDOM
Edward WETHERBEE
Yale Astronomy Department
P O Box
New Haven Connecticut
References
Kholop ov P N et al a General Catalogue of Variable Stars I th edition Moscow Nauka
Publishing House
b General Catalogue of Variable Stars I I th ed Moscow Nauka Publishing House
General Catalogue of Variable Stars I I I th ed Moscow Nauka Publishing House
Lop ez C E and Girard T M PASP 102 No
Predom C IBVS No
Shapley H and Swope H Harvard Bul letin No
Tsessevitch V P Odessa Isv 4 No
Wahlgren G M AJ 104 No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
ACCURATE POSITIONS OF SUSPECTED VARIABLE STARS
NEAR THE SOUTH GALACTIC POLE
Positions for susp ected variable stars lo cated around the South Galactic Pole were
obtained by measuring the rst ep o ch plates of the Yale San Juan Southern Prop er Motion
00
Survey The average error of the new p ositions is : in R A and Dec as referenced to
the system of the SRS
This pro ject is a continuation of a program started by Lop ez and Girard The
authors have measured variables and susp ected variables in a region around the South
Galactic Pole SGP The region centered on a R A of hours extends approximately
hours on either side The declination extends approximately from to Derived
p ositions of the variables in this region are presented in the previous issue of the IBVS
In a conversation with Dr Ho eit it was suggested that the bright stars without a
nder chart could b e lo cated relative to the eld stars on the Cordoba Atlas Using a
cuto magnitude of along with the published p osition and the references as printed in
the NSV catalogue Kukarkin et al the stars were lo cated on the CoD charts A
total of susp ected variables were lo cated in this manner and are indicated in the table
by the letter p under comments
The results listed in Table contain the following information Susp ected variable
name newly determined R A and Dec Equinox B with ep o chs in the range of
to the di erences b etween our new p ositions B and those quoted in
the NSV in minutes of time in right ascension and arc minutes in declination
and comments
As b efore we wish to thank Terry Girard Dorrit Ho eit Imants Platais Carlos Lop ez
Michael Dzubaty and esp ecially William van Altena for their guidance and supp ort
This research has b een supp orted in part by NSF grants to Yale Southern Observatory
Inc and Yale University
Rob ert DEMARTINO
Dennis KOCYLA
Christopher PREDOM
Edward WETHERBEE
Yale Astronomy Department
P O Box
New Haven Connecticut
References
Kukarkin B V et al New Catalogue of Susp ected Variable Stars Moscow Nauka
Publishing House
Lop ez C E and Girard T M PASP No
Table Positions of Susp ected Variable Stars
Variable Comments
0 00 0
NSV h m s m
p
p CoD B
p BD
p CoD
p BD
p CoD
p CoD
p Beta Cet
p BD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
Table cont
Variable Comments
0 00 0
NSV h m s m
p CoD
p BD
p CoD
p CoD
p BD
p CoD
p CoD
p BD
p CoD
p BD
p Yale
p CoD
p CoD
p CoD
p CoD
p CoD
SV Gru
p CoD
p CoD
BI Gru
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p BD
FL Aqr
p CoD
p CoD
p CoD
p
p BD
Table cont
Variable Comments
0 00 0
NSV h m s m
p CoD
p CoD
p CoD
p CoD
BN Gru
p CoD
BO Gru
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p CoD
p Aqr
p CoD
p CoD
p CoD
p CoD
p CoD
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NSV A LOW AMPLITUDE RRab STAR IN CAMELOPARDALIS
NSV BD SAO AGK PPM GSC
BV CSV was announced as a variable star by Strohmeier
and Knigge They indicated that it was an eclipsing binary with a photographic
m m
variation range from : to : without giving any further information ab out type
and p erio d According to NSV Kholop ov the sp ectral type for NSV is F
although it app ears as F in the PPM catalog
Following a surveillance program of p o orly studied variable stars NSV was ob
served for nights from December to February from L Estelot Ob
servatory in L Ametlla de Mar Spain in the B and V bands using a m telescop e
and a Starlight Xpress CCD camera As comparison star SAO BD
PPM AGK GSC was used and GSC served
as check star According to PPM the magnitude of the comparison star SAO is
and its sp ectral type is F
In order to determine the magnitude of SAO the star was observed in the B
and V bands using an Optec SSP A photo electric photometer attached to the fo cus of
the m telescop e at Mollet Observatory Spain Figure
Observations showed that NSV is not an eclipsing binary but an RR Lyrae
star with an asymmetric light curve The photometric work con rmed the
magnitude and sp ectral type of SAO This and CCD observations indicate that the
magnitude of NSV at maximum light is in V and in B which places this
m m
star among the brightest ob jects of its class The amplitude is : : magnitudes
m m
in V and : : in B
m m
The observed B V color index for this RR Lyr ranges from : to : which
means an approximate sp ectral type variation from A to F V B and B V phase
curves are depicted in Figure After checking a set of over two hundred bright RR Lyr
Lub Fitch et al Zakrzewski Eggen it was found that NSV
FW Lup and ST Pic are in this order the bright RRab Lyrae stars with the smallest
amplitude in V band
After p erforming a least squares t to the observed maxima we determined the fol
lowing ephemeris
d
Max HJD : E
Francisco CAMPOS CUCARELLA Enrique GARCIA MELENDO
Jaime NOMEN TORRES Esteve Duran Observatory
Josep M GOMEZ FORRELLAD El Montanya Seva
Grup d Estudis Astronomics SEVA
Apartado Barcelona
Barcelona Spain
Spain e mail duranobs astro gea cesca es
e mail jmgomez astro gea cesca es
References
Eggen O J Astron J
Fitch W S Wisniewski W Z and Johnson H L Communications of the Lunar
and Planetary Lab oratory No The University of Arizona Press Tucson
Kholop ov P N editor New Catalogue of Susp ected Variable Stars Moscow
Lub J Astron Astrophys Suppl
Strohmeier W and Knigge R Astronomische Nachrichten
Zakrzewski B Ro cznik Astronomiczny Observatorium Krakowskiego No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
THE NEW OVERCONTACT SYSTEM GSC IN ANDROMEDA
AND A STAR SHOWING AN OPTICAL TRANSIENT
Following a variable star search program the variability of GSC a
photovisual PAL V magnitude star according to Guide Star Catalogue was found
when taking CCD frames of the eld of PPM
In the New Catalogue of Susp ected Variable Stars Kholop ov NSV
WR a Cepheid with a photographic variation range b etween and is ab out
arcminutes to the west of GSC However in the identi cation chart originally
published by Weber WR can b e unambiguously identi ed with GSC
which is ab out degree to the north of the p osition given by Kholop ov Therefore
GSC and NSV are di erent ob jects Figure prepared from the Palomar
National Geographic So ciety Sky Survey shows the region of GSC No other
catalogued ob ject was found in the p osition of GSC
The star was observed for nights from November to February in the
V and B bands with the m telescop e of Monegrillo Observatory Spain and a CCD
Starlight Xpress camera GSC was used as comparison star and GSC
as check star Figure shows the B V and B V phase curves
Observations show that GSC is an overcontact eclipsing binary system The
m m
average amplitude in the V band is of : for minimum I and : for minimum I I The
light curve in the V band also shows an O Connell e ect O Connell that amounts
to m Max I Max I I where Max I is at phase and Max I I at
phase
Figure V GSC C Comparison star Ck Check star
Figure V B and B V phase curve of GSC
Figure V GSC and the transient optical source North is on top
From the timing of six minima see Table obtained according to the Kwee Van
Woerden metho d the following ephemeris was derived
d
Min I HJD : E
Table
HJD Minimum Ep o ch O C Filter
I V
I V
II V
I V
I B
II B
In the last CCD frame from the image series obtained on February a previously
unseen starlike ob ject was recorded with an estimated V magnitude of Figure shows
the frame which records the ob ject and the frame b efore hours are in UT A thorough
examination of the image shows that it is a ected by the same telescop e driving inaccuracy
as the rest of the stars in the same frame which indicates that it is not an image artifact
During the observation of GSC ab out CCD images were recorded but this
optical transient do es not app ear in any other one A CCD survey to detect the ob ject
at minimum light was undertaken Although the reached limiting magnitude was ab out
nothing was recorded at the p osition of this optical source whose co ordinates are
J
h m s s
R A
Dec
We thank Ricard Casas from Instituto de Astro sica de Canarias Canary Islands
Spain for his help in collecting the Palomar National Geographic So ciety Sky Survey
image of the eld of GSC and the pap er by Weber
Enrique GARCIA MELENDO
Joaquin VIDAL SAINZ
Esteve Duran Observatory
Josep M GOMEZ FORRELLAD
El Montanya Seva
Grup d Estudis Astronomics
SEVA
Apartado
Barcelona
Barcelona
Spain
Spain
e mail duranobs astro gea cesca es
e mail jmgomez astro gea cesca es
References
Kholop ov P N editor New Catalogue of Susp ected Variable Stars Moscow
Kwee K K van Woerden H BAN
O Connell D M K Riverview Pub
Weber R IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
HAS THE DELTA SCUTI STAR AD CMi A COMPANION
AD CMi is a Scuti type variable with an amplitude of magnitude and stable
light curve Jiang and Ro dr guez et al published many observations and
suggested an increasing p erio d change Ro dr guez et al and Yang et al
rep orted some new times of light maxima with the linear and quadratic solutions
To check how the star s p erio d varies with time the authors observed AD CMi again
in three nights from to February in Yunnan Astronomical Observatory
The telescop e used is a meter re ector with a conventional single channel photo electric
photometer plus a Johnson V lter From the new observational data three new maximum
times of AD CMi were determined Table lists all the times of light maxima collected
from the literature and derived from our new observations For all the data the linear
t is used to determine the calculated times of light maxima T T P E
max 01 01
The results of tting are T HJD P day s And the
01 01
O C are listed in table Then a parab olic curve is used to t the data as T
l max
2
T P E E Thus we got the tting parameters as T HJD
02 02 02
12
day s P day s day s cy cl e Figure shows the O C
02
diagram and the t curve using the parab olic function
Because many groups of data p oint distribute ab ove or b elow the t curve in Figure
which seems to suggest that there is a trigonometric function type variation we tried to
2
use the following formula to t the individual maxima T T P E E
max 03 03
A sin B cos The last two terms corresp ond to p ossible light time e ect caused by the
orbital motion whereas is the solution of the equation e sin f P E
03
in which e is the eccentricity of the elliptical orbit f the orbital frequency the time
of p eriastron Figure shows the derived O C residuals and the t curve using b oth
the parab olic and the trigonometric function The related parameters thus obtained are
as b elow
1
T HJD P days day cycle A days B days f day e res days
03 03
13 3
Figure The O C diagram and the t curve using the parab olic function
Figure The O C diagram and the t curve using the parab olic function and the
trigonometric function
Based on the t ab ove the authors tend to think that the mo del of explaining the discrep
ancies b etween the observed and calculated times of maximum light as the consequence of
a continuously changing increasing p erio d combined with the light time e ect caused
by the orbital motion of AD CMi around the mass center of a binary system with an
unseen companion is reasonable The orbital p erio d here obtained is ab out years
The rate of the p erio d change is now in agreement with the forecast of the stellar
evolution theory b oth in the direction of the p erio d changes increase and the value of
12
the rate of change day cycle However we should mention that due to
the limitation of the number of data p oints the solution provided here corresp onds to
that with the smallest residual among many p ossible solutions with di erent parameter
values It is necessary to obtain more observations esp ecially radial velocity information
to check our new mo del and determine the parameters in the end
Table Times of light maxima of AD CMi
i E T O C W Ref i E T O C W Ref
i i l i i l
Ab R
Ab Ji
Ab Ji
Ab Ji
Ab Ji
Ab Ji
Ab Ji
Ab Ji
An Ji
An Ji
An Ji
An Ji
La R
Ep R
Ba Ya
Ba Ya
Ba Ya
Ji Ya
R Ya
R Ya
R pp
R pp
R pp
Ab Abhyankar K D Ap J 130
An Anderson L R McNamara D H Publ Astr Soc Paci c 94
La Langford W R Ph Thesis Brigham Young University
Ep Epstein I Epstein A E A A J 78
Ba Balona L A Stobie R S South African Astron Obs 7
Ji Jiang S Y Chin Astron Astrophys 11
R Ro dr guez E Rolland A L opez de Co ca P Rev Mex Astron Astro s 16
R Ro dr guez E Rolland A L opez de Co ca P IBVS No
Ya Yang D W Tang Q Q and Jiang S Y IBVS No
pp present pap er
This work was supp orted by the Natural Science Foundation of China and JiangXi
Province
1 2
FU JIAN NING
1
JIANG SHI YANG
1
Beijing Astronomical Observatory Chinese Academy of Sciences Beijing
China
2
Department of Physics Nanchang University Nanchang China
References
Jiang S Y Chin Astron Astrophys
Ro dr guez E Rolland A L opez de Co ca P Rev Mex Astron Astro s
Ro dr guez E Rolland A L opez de Co ca P IBVS No
Yang D W Tang Q Q and Jiang S Y IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
A H FLARE ON UV PISCIUM
m
UV Psc HD m : P days is an eclipsing sp ectroscopic system clas
v
si ed with the short p erio d group of RS CVns This system has b een studied in sev
eral pap ers but its prop erties are still not well established e g for the sp ectral types
of the comp onents Barden determined G K IV while Popper suggested
G V K V The sp ectroscopic observations of UV Psc made by Popper in
dicate that the system is a double line binary with emissions from b oth comp onents in
the H and K lines of CaI I though the co oler comp onent contributes only weakly to the
sp ectrum the contribution from the hotter comp onent is L L L in V The
presence of a prominence in UV Psc was revealed by sp ectral subtraction in the H order
Hall and Ramsey
We observed UV Psc in the H region during November with the aim of studying
the rotational mo dulation at chromospheric levels The observations were carried out with
the All Fib er Coupler grating sp ectrograph of the m telescop e at Beijing Observatory
The recipro cal linear disp ersion was A mm at H and the detector was a CCD
array with pixels The pixel to pixel resolution of the detector comes to A
A signal to noise ratio S N of ab out in the H continuum was reached with
typical exp osure times of minutes The sp ectra extracted from the CCD images with
a standard reduction pro cedure and calibrated in wavelength using a comparison neon
lamp were normalized to the continuum through a p olynomial t
We have measured the net H equivalent width WH after subtracting an average
sp ectrum of the single non active star Cas A from our sp ectra The reference sp ectrum
was appropriately shifted in wavelength in order to account for orbital Doppler shifts of
the visible comp onent in the sp ectrum This metho d allows us to get a b etter estimate
of the emission equivalent width even when the observed line pro le is only marginally
lled in by emission
UV Psc has b een observed for ve nights from November to when
sp ectra were obtained These cover most of the orbital phase except an interval of the
phase from to The phases were computed according to the ephemeris given by
Jassur and Kermani
T E
Figure shows the secondary order sp ectra around H for UV Psc and the reference
star which were obtained on the nd Nov The net H emission equivalent width
computed from the observations obtained on the nd are plotted against the orbital
phases in Figure
Figure H sp ectra of UV Psc obtained on nd Nov The sp ectrum of the
reference star Cas A is presented in the b ottom of the plot
Figure H emission equivalent width as a function of the orbital phase
In our observations H line app ears to b e an absorption feature lled in by some
emission but remarkable variations in the H pro le are clearly displayed in the plots
Esp ecially it is p ossible that such variations in the H pro le and the net emission
equivalent width values suggest a complete development of a H are in UV Psc The
are curve is characterized by a fast rising phase lasting ab out hours and a slow
decay phase lasting ab out hours Before rising a small concave seems to o ccur near
the phase and after the rst decay a small hump clearly o ccurred near the phase
This b ehaviour indicates that the are is comp osed of at least two events Multiple
events are often seen in other RS CVn systems as well as in UV Cet type stars This long
duration hours is shorter than the typical duration of single are in RS CVn stars
hours and may b e compared with the solar two ribb on are duration hours
LIU QUINGYAO
YANG YULAN
GU SHENGHONG
HANG ZHANKUI
Yunnan Observatory
Chinese Academy of Sciences
Kunming Yunnan Province
China
References
Barden S C ApJ
Hall J C and Ramsey L W AJ
Jassur D M Z and Kermani M H Ap SS
Popper D M IBVS No
Popper D M AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
UBV PHOTOMETRY OF V Per
V Per DHK is an Algol type system discovered by Kaiser et al Very
little is known ab out the system Photo electric observations reveal a primary minimum
m
of and the secondary minimum is almost insigni cant
New observation of V Per were made on nights during observing
season with the cm Maksutov telescop e of Ankara University Observatory Di erential
observations were secured by using an EMI QB photomultiplier All observations
were made with Johnson s UBV lters The comparison star was BD and check
stars were BD and BD The standard deviations of the comparison
m m m
minus check stars measurements are U B and V These values
were averaged over the all comparison minus check measurements The light and colour
curves of V Per are plotted in Figure by using the ephemeris given by Kaiser et al
as
d
Min I HJD E
One minimum time is obtained from our own observations by using Kwee and van
Woerden s metho d
Min I HJD
The observational data can b e obtained from the authors
Figure shows that phasing and thus the light elements by Kaiser et al do not
need any revision The phases outside eclipse are not well covered in Figure and no
appreciable proximity e ect is visible We therefore attempted the solution of the B and
V light curves by using a simple spherical mo del assumption see Kopal and Demircan
and Demircan The mean solution as given in Table indicates that the
system is highly interacting with relatively large fractional radii of the comp onents and
thus the proximity e ects would not b e negligible We therefore think the system deserves
further photometric and sp ectroscopic study
The observational data can b e obtained from authors
Table Some orbital parameters of V Per
r r L U i K
fractional fractional fractional E
B
V
Av
Figure The light and colour curves of V Per Solid line represents theoretical light
curve
We thank Prof Dr O Demircan for his encouragement and guidance
SACIT OZDEMIR
MEHMET TANRIVER
Ankara University Observatory
Faculty of Science
Tando gan Ankara
Turkey
References
Demircan O PhD Thesis The University of Manchester
Kaiser D H Baldwin M E and Williams D B IBVS No
Kopal Z and Demircan O Ap SpSci
Kwee K K and van Woerden H Bul l Astron Inst Neth
COMMISSIONS AND OF THE IAU
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Konkoly Observatory
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April
HU ISSN
OBSERVATIONS OF THE FLARE STAR V CYGNI
V Cyg was discovered during the monitoring campaign for are star search based
on the photographic patrol observations with the Asiago cm Schmidt telescop e in
h m
the region of the NGC nebula This star with co ordinates R A :
Dec got rst designation A Rosino et al According to
the th Name list of Variable Stars Kholop ov et al the star is named V
Cygni During the are event on September the star increased its brightness up
m
to : pg V Cyg is obviously lo cated near the V Cyg LkH group of
H emission and are stars in the star forming region of the dark nebula Gulf of Mexico
in the North America nebula In Figure the identi cation map of the star from an
minute exp osed V plate Ko dak aD GG obtained with the cm Byurakan
Schmidt telescop e on April is given
Here we present results of sp ectroscopic and photometric observations of V Cyg
in quiescence
Figure The identi cation map of V Cyg North is up east is to the left
Figure The sp ectra of the are star V Cyg in the blue top and red b ottom
Here we present results of sp ectroscopic and photometric observations of V Cyg
in quiescence
The sp ectroscopic observations were made with the m telescop e of the Sp ecial Astro
physical Observatory of the Russian Academy of Sciences and the channel television
sp ectrophotometer scanner with SP sp ectrograph Drab ek et al during the
night of Octob er The lines mm di raction grating with e ective resolution
of ab out A was used The standardization of the sp ectra by observing a well known
standard star following the work of Bares and Hayes was done A preliminary
analysis of the sp ectra subtraction of the sky background correction for inhomogeneities
in the photo catho de sensitivity construction of disp ersion curves and linearization of
the wavelength scale was carried out according to Somov Further analysis of the
sp ectra correction for sp ectral sensitivity of the system smo othing by means of gaus
sians calculations of physical parameters was done using the Byurakan Astronomical
Data Analysing system ADA Zaratsyan and Maghakyan The observed two are
star sp ectra cover the visible region of the sp ectrum A In Figure the sp ectra
of V Cygni in the blue and red sp ectral ranges are shown
The CCD photometric observations were made in the Rozhen Observatory of the In
stitute of Astronomy Bulgarian Academy of Sciences with the m RCC telescop e and
ST CCD camera on November A series of two sec exp osures in B and
V and sec exp osures in R and I Kron was obtained The photometric reductions
were made with a software package according to Georgiev et al with the WFPDB
computer complex The magnitudes and colours of the star derived from the photometric
BVRI observations after the extinction corrections are
m m m m
V : B V : V R : V I :
According to this data V Cyg is one of the brightest are stars in the eld of NCG
nebula
V Cyg is included neither in the list of IRAS p oint sources nor in X ray ROSAT
catalogue This fact could b e due to the faintness of the star and do es not exclude the
resp ective requirements for registration in these catalogues
The sp ectroscopic observations suggest that the star is of sp ectral type dK dK with
H line in emission having in mind the strong relation of the TiO sp ectral band
with the sp ectral type of the stars of sp ectral classes dK dM Pritchet and van den
Bergh Pettersen and Hawley
The photometric values indicate estimation of the sp ectral class dK e according to
m m m
Zombeck s standard colours B V : V R : and V I : for stars
of dK sp ectral type Using the data for absolute magnitudes and colours for dK stars we
m
obtained a distance mo dulus of m M : The maximum distance to V Cyg
v
would b e p c with the assumption for lack of interstellar absorption As the average
value of A for some near situated H emission stars like LkH is estimated by
v
m
we derived ab out p c for the distance to Cohen and Kuhi to b e ab out
the are star Taking into account that the distance to the NGC aggregate is
p c Tsvetkov we conclude that V Cyg b elongs to the nearest part of this star forming region
This work was partly supp orted by grants F and F of the National
Science Fund of the Bulgarian Ministry of Education Science and Technology
Milcho TSVETKOV
Evgeni SEMKOV
Katya TSVETKOVA
Institute of Astronomy
Bulgarian Academy of Sciences
E mail FSDB bgcict acad bg
Valery HAMBARYAN
Byurakan Observatory
Armenian Academy of Sciences
E mail Byurakan pnas sci am
References
Bares J V Hayes D S IRS Standard Manual Kitt Peak National Observatory
Cohen M and Kuhi L ApJ SS No
Drab ek S V Kopylov I M Somov N N Somova T A Astrophys Issled Izv
Spets Astro z Obs
Georgiev Ts Getov R Semkov E Mutafov A Todorova H The IAU Working
Group on Wide Field Imaging Newsletter
Kholop ov P N Samus N N Kazarovets E V Frolov M S Kireeva N N IBVS
No
Pettersen B R Hawley S L Publ Inst of Theor Astroph Oslo University
No
Pritchet Ch van den Bergh S ApJ SS
Rosino L Tsvetkov M Tsvetkova K IBVS No
Somov N N Astrophys Issled Izv Spets Astro z Obs
Tsvetkov M K PhD Thesis Yerevan University
Zaratsyan S V Maghakyan T Yu Soobshch Byurakan Obs
Zombeck M V Handbook of Space Astronomy and Astrophysics Cambridge Uni Press Cambridge
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
NEW VARIABLE STARS IN CYGNUS LACERTA AND ANDROMEDA
h m
The following is an evaluation of an area of centered at
in my series of elds in the Milky Way Three elds have b een previously describ ed
Dahlmark
Eighteen plate pairs Ko dak aD GG and aO were exp osed b etween
and and were exp osed on Ko dak TechPan Schott lter in the years
to All exp osures were made with f mm optics They are examined in the
same way as describ ed by Dahlmark Magnitude estimations of comparison
stars were transferred from the sequences in NGC and published by Hoag et al
In this survey stars are published of which are new variables The results are
based on ab out magnitude estimates for each star The lightcurves have b een used to
determine the provisional variability type ep o ch and p erio d for long p erio d variable
stars
The nding charts are based on mm Schmidt camera photographs ob
tained in August
Lennart DAHLMARK
Montlaux
F St Etienne les Orgues
France
References
Dahlmark L I B V S No
Dahlmark L I B V S No
Dahlmark L I B V S No
Hoag A et al Publ U S Naval Obs
Figure
h m
Table New variables in And Cyg and Lac Plate centre
No R A Decl m m B V Type Ep o ch Period Notes
v v
max min d
h m s 0
LD : : SR
LD SRD
LD
LD
LD M
LD
LD >
LD
LD M
LD
LD >
LD > NL
LD SR
LD > SR
LD
LD > M
LD
LD
LD > M
LD > M
LD M
LD M
LD > M
LD >
LD > M
LD > M
LD SR
LD
LD M
LD
LD
LD SRD
LD > M
LD >
LD M
Notes
IRAS star
Close faint star may in uence magnitude estimates at minimum
Could b e V or V Cyg
Period increasing
FK Lac
Period variable
Period increased from to days
NSV p erio d varies from to d
Maxima only in and
m
in min column means that star is fainter than :
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
April
HU ISSN
UBV OBSERVATIONS OF AB Dor LATE
Monitoring of the rapidly rotating co ol early K type and relatively bright dwarf AB
Dor HD SAO is needed for a fuller account of the prop erties of elec
tro dynamically active stars cf Vilhu et al Collier Cameron and references
cited therein The ephemeris of Innis et al Min E
is usually used to calculate phase values for reference purp oses
The star was observed in B and V ranges on go o d nights in Sep and and
Dec and with the cm F S C telescop e and DC photometer of the Mt Molehill
Observatory cf Bos and Oct with the automated photometer APT at the
Kotipu Place Observatory KPO using the UBV lters provided with the SSP Optec
photometer cf Hudson et al
Standard reduction pro cedures have b een followed cf e g Budding The main
comparison star was again HD V B V U B sp ectral
type K I I I cf SIMBAD This comparison was regularly checked against HD
at Mt Molehill Table Measurements were made every minutes dep ending on
conditions At KPO HD was checked against HD also a K I I I star Budding
et al The vagaries of the check against comparison are typically mag in the
data sets presented although sometimes reaching The scatter of individual p oints
is somewhat greater for the KPO data and also greater in B than in V data
These data sets are shown in Figures and Figure combines the Mt Molehill Bos
and KPO data since there app ears to b e a general continuity for the September Octob er
p erio d Figure shows the December data The U data from KPO for Oct follows
the trend of the other two B V data sets but it is not plotted here The U magnitude
ranges from ab out at phase to at phase with a typical scatter of
mag
Table Variability of AB Dor amplitude and minimum phase
Max Min Amplitude Phase
Figure a
Figure b
Figure a
Figure b
Figure AB Dor B V light curves for Sep Oct
Figure AB Dor B V light curves for Dec
The observed minima may b e related to sp ot A of Innis et al rather than
sp ot B but in view of the apparent tendency of the minima to move downward in phase
rep orted b efore Bos et al and evident in the trend for late indicated in
this article the old scheme of Innis et al is rather placed in doubt One p ossibility is
that another value of the p erio d will give a b etter general representation of the variation
resulting from macul which would b e at xed longitudes A shorter p erio d of d
has b een suggested by Bos This p erio d pro duces a well rep etitive light curve
with a steady minimum at phase through
The maximum brightness of AB Dor increased slightly up to in V since the
and observations The relatively longer prop ortion of darkened time on the
data sets cannot b e repro duced with just one large starsp ot however Sp ottedness
must cover an appreciable range of longitude in the September Octob er p erio d though
the relatively unsp otted cusp like phase range has widened out somewhat by December
Observations have continued from late into and the more recent data retains
a consistent phasing of the minima with using the shorter p erio d of Bos
These newer data will b e rep orted separately later
M BOS
G HUDSON
R HUDSON
E BUDDING
Mt Molehill Observatory Auckland
Kotipu Place Observatory Pukerua Bay
Carter Observatory Wellington and
Central Institute of Technology
Heretaunga New Zealand
References
Bos M IBVS No
Bos M Budding E Hudson G and Hudson R IBVS No
Budding E An Introduction to Astronomical Photometry Cambridge Univ Press
Cambridge
Budding E Hudson G and Hudson R IBVS No
Collier Cameron A Preprint submitted to Mon Not Royal 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
Innis J L Thompson K Coates D W and Lloyd Evans T Mon Not Roy
Astron Soc
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
April
HU ISSN
HD A NEW ECLIPSING BINARY
IN THE OPEN CLUSTER M NGC
We carried out time series CCD photometry of M for ve nights from August
to September The observations were made with a Photometrics PM CCD
camera and Johnson V lter which were attached to the cm Ritchey Chr etientelescop e
at Seoul National University Observatory SNUO The size of the eld in the CCD image
is arcsec pixel at the f Cassegrain fo cus of the telescop e The exp osure
time and the duty cycle were sec and sec resp ectively The photometric seeing was
typically during the observation p erio d The nding chart is shown in Figure We
monitored stars of M dividing into four elds
The prepro cessing of CCD images was made with the IRAF CCDRED package De
fective pixels of our CCD chip Sung were corrected and the trimming of unreliable
subsection was applied Then we pro ceeded with the bias dark and at eld corrections
We adopted simple ap erture photometry to obtain instrumental magnitudes using the
IRAF APPHOT package Massey Davis Total probable errors are estimated
m m
to b e ab out mmag for stars
We applied the classical two star di erential photometry to get standard magnitudes
Instrumental magnitudes were scaled comparing with the comparison star HD
No in Figure as follows
V v V v
i i
where v is the instrumental magnitude of the i th star and the magnitude of the com
i
parison star V was calculated from previously known values Mermilliod
It corresp onds to the standard magnitude if the di erence of the color correction term
b etween the comparison star and the others B V is negligible the color
V
co e cient of our lter system is nearly zero Sung and the color di erence
V
m
b etween the stars is mostly smaller than
Table Photometric prop erties of observed stars
y
z z z
Star Name V B V U B Remark ID ID
O U RS
S
HD Variable star
HD Check star
HD Check star
HD Comparison star
y z
Sanders Massey et al
Figure Finding chart of M The new eclipsing binary and three comparison
stars are denoted as op en circles
Figure Light variations of HD and two check stars
HD has a high value of membership probability which was deduced from
the prop er motion Sanders But it do es not lo cate in the normal evolution sequence
at the C M diagram indicating that it is a evolutionary p eculiar star Joshi et al
or a non member star Crawford Barnes From the radial velocity measurements
it was known as a sp ectroscopic binary Liu et al We detected clearly its light
variation for one night J D Its light curves Figure are similar to that of
an Algol type eclipsing binary Ho meister et al Though it is the brightest star
in M its light variation has not b een rep orted so far Kholop ov et al
Our observations suggest that it is an eclipsing binary with a minimum brightness near
m
HJD and an amplitude of at least
S L KIM
S W LEE
Korea Astronomy Observatory
Department of Astronomy
Taejon
Seoul National University
Korea
Seoul
e mail slkim seeru b oao re kr
Korea
References
Crawford D L Barnes J V AJ
Ho meister C Richter G Wenzel W in Variable stars Springer p
Joshi U C Sanwal B B Sagar R PASJ
Kholop ov P N Samus N N Frolov M S Goranskij V P Gorynya N A Kireeva
N N Kukarkina N P Kuro chkin N E Medvedeva G I Perova N B
Shugarov S Yu in General Catalogue of Variable Stars th Edi
tion Moscow Nauka Publishing House
Liu T Janes K A Bania T M AJ
Massey P Davis L E A User s Guide to Stel lar CCD photometry with IRAF
Massey P Johnson K E DeGioia Eastwoo d K ApJ
Mermilliod J C A AS
Sanders W L A AS
Sung H Ph D Dissertation Seoul National University
COMMISSIONS AND OF THE IAU
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Number
Konkoly Observatory
Budap est
April
HU ISSN
V CASSIOPEIAE IS AN RR LYRAE TYPE VARIABLE
BAV Mitteilungen Nr
V Cas S Cas was discovered by Ho meister on photographic plates
of the Sonneb erg Observatory He classi ed this star as a short p erio d variable in the
m m
range b etween : and p ossibly eclipsing First investigation of this variable was
m
p erformed by Meinunger She determined the range of variability b etween :
m
to : and gave rst elements as
d
Min I HJD : E
V Cas was cited again as eclipsing variable in a pap er by Gessner and Meinunger
in which the authors note that the investigation of this variable was handicapp ed
by its relative high brightness and small amplitude They gave eight times of minima and
mentioned that the ab ove elements may not b e regarded as ascertained With these data
V Cas is listed in the fourth edition of the GCVS Kholop ov et al
For a quarter of a century the variable had not b een observed when we put V Cas
on our observing program The CCD observations were made with SBIG ST cameras
without lters attached to a cm RC telescop e W M and a cm SC telescop e F A
m
GSC : served as comparison star
A p erio d analysis program based on the algorithm of Schwarzenberg Czerny
resulted in a p erio d roughly double as long as the GCVS p erio d As our CCD observations
show the variable is of RR Lyr type with a rather long p erio d and small amplitude In
m p
our instrumental system the amplitude of variability is : and M m :
To expand our knowledge of p erio d changes to the past one of us E S investigated
this star on plates of the Sonneb erg Sky Patrol
The timespan covered by these plates was divided into several parts
Using a rst ephemeris for each of these parts a mean lightcurve was calculated and the
time of the normal maximum was derived W K see Table From that moments
of normal maximum light resulted The O C residuals are shown plotted in Figure
Obviously the p erio d did not remain constant in the investigated interval of time
Considering the accuracy of estimates on photographic plates the p erio d probably changed
at ab out JD
Least squares ts in each of these intervals yield the following linear elements
d
Max I HJD : E
valid b etween JD and JD and
Table Times of maxima for V Cas 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
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
E
E
E
E
E
E
E
E
E
E
E
?
E denotes CCD observed maxima P are photographic Those marked with
got reduced weight
E Splittgerb er W Kleikamp W Moschner F Agerer
Figure Di erential light curve of V Cas with resp ect to the new ephemeris
Figure O C diagram for V Cas computed with resp ect to Max
HJD E using all available maximum timings represents
photo electric and photographic normal maxima 2
d
Max I HJD : E
valid after JD
F AGERER
W KLEIKAMP
W MOSCHNER
E SPLITTGERBER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm
D Berlin Germany
References
Gessner H Meinunger I Ver o Sternw Sonneberg
Ho meister C Astr Nachr
th
Kholop ov P N et al Gen Cat of Var Stars Ed Nauka Moscow
Meinunger I Mitt Ver Sterne Sonneberg
Schwarzenberg Czerny A Mon Not R Astr Soc
COMMISSIONS AND OF THE IAU
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Number
Konkoly Observatory
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April
HU ISSN
GSC A NEW W UMa TYPE ECLIPSING BINARY
IN THE FIELD OF GG Ori
During our observational pro ject initiated in with the main purp ose to monitor
eclipsing binaries with eccentric orbit we found in the eld of GG Ori that the star
GSC is a new eclipsing binary of W UMa type with a p erio d of ab out days
The variability of this star was discovered at the R Szafraniec Observatory Metzerlen
Switzerland in Octob er using a cm Cassegrain telescop e equipp ed with an
h m s
SBIG ST CCD camera The co ordinates of this star are s
equinox its V magnitude given in the Guide Star Catalogue is mag
The next precise CCD photometry of this star was carried out during nights from
December to February at Ond rejov Observatory Czech Republic A
cm re ecting telescop e with the same type of CCD camera was used The measurements
were done using the standard Cousins R lter with exp osure time b etween and s
The nearby stars GSC V mag and GSC V mag on the
same frame as the new variable served as the comparison and check stars resp ectively
No variations in the brightness of these stars were detected exceeding the standard errors
of the measurements in R during observations Altogether frames of this eld were
obtained and analyzed The CCD data were reduced using the software developed at
Ond rejov Observatory by P Pravec and M Velen Pravec et al The precise
times of minima and their errors were determined using the Kwee van Woerden
metho d These moments are listed in Table In this table N stands for the number
of observations used in the calculation of the minimum time Figure gives the nding
chart Figure shows the comp osite R light curve According to our measurements the
amplitude is mag The light curve was solved using a new metho d of treating
photometric data describ ed by Mikul a sek et al This metho d is a weighted LSM
iterative pro cedure where the mo del function for the light curve of the W UMa eclipsing
binaries has a form
X
A cos if A G f m K f
i
i
where
G f cos f cos f cos f
Figure Finding chart of GSC The eclipsing binary GG Ori and the
comparison and check stars are also plotted
Figure Comp osite R light curve of GSC
Table Moments of minima of GSC
JD Hel Ep o ch Error N
days
where f is the photometric phase and m is the average magnitude of the star The
co e cients A A A describ e the light curve with equal depths of primary and secondary
minimum see the pap er mentioned ab ove for more details Using this metho d we derive
the following linear light elements for the current use
d
Pri Min HJD E
As a reference time we have chosen the approximate midp oint of the observation in
terval
Acknowledgment This work has b een supp orted in part by the Grant Agency of the
Czech Republic grant No and by the ESO C EE Programme grant No
A We also gratefully acknowledge the assistance of the Cokol adovny ORION
a s which supp orts the variable stars research in this constellation We are thankful
to Dr Roger Diethelm R Szafraniec Observatory Metzerlen in providing time for our
CCD observations in Octob er We would like to thank Dr Zden ek Mikul a sek N
Cop ernicus Observatory Brno for the valuable discussion of his new metho d
Marek WOLF
Lenka SAROUNOVA
Astronomical Institute
Charles University Prague
CZ Praha
Sv edsk a
Czech Republic
Internet wolf mbox cesnet cz
References
Kwee K K Van Woerden H Bul l Astron Inst Neth
Mikul a sek Z Han zl D Horno ch K Contributions Nicholas Copernicus Obser
vatory Brno
Pravec P Tich y M Tich a J Moravec Z V avrov a Z Velen M Planet Space
Sci
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
LIGHT CURVES AND PERIODS OF THE RR LYRAE STARS
SU Cha AND SW Cha
A system of dark clouds in the constellation Chamaeleon was rst investigated by
Ho meister who detected a large number of variable stars many of which b eing
members of what is now called the Cha T asso ciation In a search for are events in
this region Winterberg Winterberg et al we found two variables which were
identi ed with Ho meister s variables SU Cha classi ed as RR Lyr star and SW Cha
which is misclassi ed in the GCVS Kholop ov et al as b eing of type Is and which
many authors regard as a member of the Cha T asso ciation However we unambiguously
identify it as another RR Lyr star unrelated to the asso ciation
During four observing runs in and a total of multiple exp osure
plates in nights were obtained on I Ia O plates at ESO s cm GPO telescop e at La
Silla Each plate contains chains of in general exp osures of minutes each
An automatized routine was used to separate the individual exp osures on each plate
and to determine magnitudes The co ordinate transformation based on PPM stars
00
R oser Bastian Bastian et al is accurate to within Magnitudes
were determined using metho ds developed by Cunow Since all standard stars
are rather bright an extrap olation was required for the fainter stars on the photographic
plate Thus in addition to statistical uncertainties faint magnitudes may su er from
systematic errors Therefore not much weight should b e given to the absolute values
of the magnitude scale Period determination is however not a ected by these errors
For further details concerning the reduction pro cedures see Aniol and Winterberg
SU Cha
SU Cha was detected as a variable star of RR Lyr type by Ho meister who gave
it the preliminary designation S He derived a p erio d of days The nding
chart published by Ho meister leaves no doubt that the star we detected in our
h m s
observations is identical to SU Cha Improved co ordinates are
0 00
and A light curve was published by Gessner con rming
the original classi cation She found the p erio d to b e days No further observations
of SU Cha have come to our knowledge
Our observations are distributed over a time base of years An Analysis of Variance
p erio dogram AoV Schwarzenberg Czerny was calculated from our data and
yielded a highly signi cant p eak The light curve folded on the corresp onding p erio d
is shown in Figure It is typical for RRab type stars We derived a p erio d and an ep o ch
of maximum as given by the ephemeris
d
Max HJD E
Here the error of the p erio d is arbitrarily and conservatively xed to a value which
would lead to an easily recognizable phase shift of over the entire time base of the
observations Similarly the error of the zerop oint is xed at of the pulsation p erio d
13.5 14
SU Cha SW Cha
14 14.5
14.5 15 pg pg m m
15 15.5
15.5
16
0 0.5 1 0 0.5 1
Phase Phase
Figure Light curve of SU Cha folded on Figure Light curve of SW Cha folded
the pulsation p erio d days on the pulsation p erio d days
The p erio d is practically identical with that found by Gessner but more accurate
She quotes times of maximum for the observing season of SU Cha This p ermits
to calculate O C values over a long time base using the ab ove p erio d and maximum
ep o ch The mean value is as small as days days assuming
that Gessner did not apply the helio centric correction indicating that the derived p erio d
leads to negligible phase errors over a time base of more than years Taking the mean
O C value and its statistical error as indicative of the true uncertainty of the p erio d a
more realistic error should then b e days instead of the conservative estimate of
days quoted ab ove
SW Cha
The literature on SW Cha is somewhat more extensive than that of SU Cha alb eit not
much SW Cha was also discovered by Ho meister who gave it the preliminary
designation S The chart published by Ho meister again leaves no doubt that
h m s
the star discussed here is indeed SW Cha Improved co ordinates are
0 00
and It was originally classi ed as similar to RW Aur
while according to the GCVS it is of type Is Gessner susp ected SW Cha to b e
an RR Lyr star She quotes four ep o chs of brightenings but do es not show a light curve
Rydgren to ok a single photometric measurement in UBVri r and i b eing non
standard bands Assuming that SW Cha is a member of the Cha T asso ciation he found
it to lie b elow the main sequence He concluded that SW Cha is probably a background
ob ject unrelated to the asso ciation This is also supp orted by the fact that unlike many
other members of the Cha T asso ciation SW Cha was not detected by IRAS Gauvin
and Strom However for reasons which are not quite obvious Whittet et al
classify it as a member and subsequent publications Gregorio Hetem et al Gauvin
and Strom Schwartz Hartigan do not put the membership into question
However we show b eyond any reasonable doubt that SW Cha is not a member of the
Cha T asso ciation and that Ho meister s original classi cation was erroneous In
contrast Gessner s suspicion was correct
Using the same pro cedure as in the previous case we unambiguously found a p erio dic
variation in the brightness of SW Cha The AoV p erio dogram showed also in this case
a highly signi cant p eak The light curve folded on the corresp onding p erio d is shown
in Figure The shap e of the light curve together with the value of the p erio d leave no
doubt ab out the classi cation of SW Cha as an RRab type star The ephemeris for the
maxima is
d
Max HJD E
The errors are de ned in the same way as in the case of SU Cha
Interpreting the four ep o chs of brightening quoted by Gessner as genuine max
ima the ab ove ephemeris leads to a mean O C value of days Taken
at face value this would indicate that the true p erio d assuming a constant p erio d is
days shorter just consistent with the conservative error However the
observed brightenings need not necessarily corresp ond to the true maxima but to nearby
ep o chs with a higher probability for lying after a maximum than b efore considering the
shap e of the light curve Then the true p erio d may b e somewhere b etween the one given
in the ephemeris and a p erio d shorter by days
Schwartz lists in his Table a sp ectral type of M for SW Cha The source of
this classi cation remains unclear It do es not t in with the colours B V and
U B measured by Rydgren In contrast the colours are consistent with
those of a highly reddened E star of type A I I I F I I Schmidt Kaler
B V
This is well in the range of RR Lyr stars and the dereddened colours also corresp ond to
an RR Lyrae star Club e et al
Our clear detection of an RR Lyr type variability in SW Cha is at o dds with the mag
nitude estimates of Mauder and Sosna p erformed on the basis of photographic
plates taken over a time base of days The light curve constructed from their table was
also sub jected to an AoV analysis No indications of a p erio dic variation on time scales
ab ove an hour were detected It is not clear why Mauder s and Sosna s data do not show
any sign of p erio dic variability which is so clearly present in our observations
We have obtained light curves of two RRab type variable stars SU Cha and SW Cha
While the former was already known as an RR Lyr star the latter was previously classi ed
as b eing of type Is However the light curve observed here leaves no doubt ab out the
correct classi cation The pulsation p erio d of SU Cha could b e derived to a signi cantly
higher precision than hitherto known that of SW Cha could also b e determined with a
su ciently high precision to p ermit secure cycle counts for several decades Although the
unknown interstellar extinction and the errors of our photographic photometry do not
allow us to make useful statements ab out the distance of b oth stars it is obvious that
SW Cha cannot b e a member of the Cha T asso ciation which is at a distance of only
p c Whittet et al and should b e discarded from corresp onding lists in the
literature Astrometric measurements lead to p ositions which are signi cantly improved
compared to the original co ordinates determined by Ho meister and quoted in the
GCVS
J urgen WINTERBERG
Alb ert BRUCH
Astronomisches Institut
Wilhelm Klemm Str
D M unster
Germany
References
Aniol R Automation und erste Ergebnisse einer Flare Stern Durchmusterung
Diploma thesis M unster
Bastian U R oser S Nesterov V V Polozhentsev D D Potter Kh I Wielen R
Yagudin L I Yatskiv Ya S A AS
Club e S V M Evans D S Jones D H P Mem RAS
Cunow B A A
Gauvin L S Strom K M ApJ
Gessner H Ver o Sternw Sonneberg
Gregorio Hetem J C L epine J R D Ortiz R P Rev Mex A A
Hartigan P AJ
Ho meister C ZsAp
Ho meister C Ver o Sternw Sonneberg No
Kholop ov P N Samus N N Frolov M S Goranskij V P Gorynya N A Kireeva
N N Kukarkina N P Medvedeva G I Perova N B Shugarov S Yu Gen
eral Catalogue of Variable Stars Vol I Moscow
Mauder H Sosna F M IBVS No
R oser S Bastian U A AS
Rydgren A E AJ
Schmidt Kaler T in K Schaifers H H Voigt eds Landolt B ornstein Nu
merical Data and Functional Relationships in Science and Technology New Series
Group VI Vol Subvol b Springer Verlag Heidelb erg p
Schwartz R D in B Reipurth ed Low Mass Star Formation in Southern
Molecular Clouds ESO Scienti c Rep ort No p
Schwarzenberg Czerny A MNRAS
Whittet D C B Kirrane T M Kilkenny D Oates A P Watson F G King D J
MNRAS
Winterberg J Flare Sterne in Sternhaufen und Assoziationen Automatische
Suche und Analyse in den Regionen Orion M Sco Oph und Cha T Diploma
thesis M unster
Winterberg J Nolte M Seitter W C Duerb eck H W Tsvetkov M K Tsvetkova
K P in J Greiner H W Duerb eck R E Gershberg eds Flares and
Flashes Pro c IAU Coll Springer Verlag Berlin pp
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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May
HU ISSN
OBSERVATIONS OF LOW AMPLITUDE LATE TYPE VARIABLES
2
The low amplitude red giant variables UX Dra Lyr VY UMa and RR UMi have
b een observed almost continuously since mid as part of a programme to investigate
known and susp ected red variables UX Dra and VY UMa are very similar stars they
2
are b oth luminous carb on stars with Tc Little et al while RR UMi and Lyr are
less evolved AGB stars Jorissen et al Eggen
The observations were made using an SSP photometer and nominal V lter on a
cm Newtonian re ector Each observation consisted of or sets of second
integrations Di erential extinction corrections were applied but these are small Details
of the comparison stars are given in Table For further information please contact the
authors
UX Dra HD SAO BD has a sp ectral type of C I I and according
to the GCVS Kholop ov et al is an SRa with a p erio d of days From times
of minimum Vetesnik found a constant increase of the p erio d but more extensive
photographic data suggested that this was part of a long term cycling of the p erio d
b etween and days over ab out days In the light curve of UX Dra Figure
the largest variations have a p erio d of days sup erimp osed on a large gradient
However the earliest observations show a variation of only mag on a time scale of
days As the published day p erio d app ears in these data it seems unlikely that
Figure Light curve of UX Dra
2
Figure Light curve of Lyr
the p erio d is variable The time of lower activity may indicate that the b ehaviour sug
gested by Vetesnik is due to phase changes in this relatively stable p erio d
2
Lyr HR HD SAO is a fourth magnitude star of sp ectral type
M I I Photometry during the s led Bakos Tremko to conclude that it is a
semi regular variable with a characteristic time scale in the range days Sup erim
p osed on this are longer term variations in the mean magnitude and shorter term excur
sions of similar amplitude On the basis of the variation in the annual light curves Bakos
Tremko were unable to suggest a single p erio d but concluded that the p erio d was variable
The dominant feature of the new observations Figure is a strong p erio dicity at
2
Figure DFT p ower sp ectrum of the new photometry of Lyr combined with that of Bakos Tremko
Table Comparison star information
Variable Comparison V B V Sp V
UX Dra HR HD A V
HR HD F V
2
Lyr HR HD B V
HR HD B IV
VY UMa HR HD K I I I
HR HD K I I I
RR UMi HR HD F IV
HR HD A Vs
days but many of the characteristics seen previously are also visible The p erio dogram
of the combined photometry Figure is dominated by a long term variation which is
1
not necessarily p erio dic and a p erio d of days f cycles day together with
2
their one year aliases Lyr has a complex light curve with many time scales but the
day p erio d is su ciently stable to app ear in observations covering the past years
and is the dominant short term feature of the data
VY UMa HR HD SAO BD is of sp ectral type C I I and
is given by the GCVS as an Lb variable Analysis of visual data covering
shows a p erio d of days Ofek Shemmer Gabzo The AAVSO photo electric
observations which are admittedly rather sparse suggest a variation on a time scale of
days Percy et al but these cover the years when the b ehaviour
may have b een di erent The p erio dogram of the new data in Figure shows a clear
p erio d at days and this is a remarkably go o d t to most of the data The amplitude
is clearly variable but for the most part the p erio d is relatively stable and even after
there is some disruption the phasing is retained As there is no overlap b etween these data
and the visual observations it seems likely that the day p erio d dominated for most of
the past six years However the absence of this p erio d in the AAVSO data suggests that
it was probably not dominant b efore that
Figure Light curve of VY UMa with the day p erio d sup erimp osed
Figure Light curve of RR UMi
RR UMi HR HD SAO BD has a sp ectral type of M I I I
and is one of the few semi regular variables in a binary with a known orbit Batten
Fletcher The p erio d is days but there is no indication of the secondary RR
UMi is listed in the GCVS as an SRb with a p erio d of days but variations on a range
of time scales from days have b een found by Percy et al The p erio dogram
of the light curve in Figure shows no dominant p erio d although p erio ds of and
days are present A suggestion of the day p erio d can b e followed through the rst
half of the data but then b ecomes quickly lost During the second half of the data the
time scale of the variation halves which is probably resp onsible for the day p erio d in
the p erio dogram RR UMi shows variation on the day time scale with no dominant
p erio d in the present data There is no indication of a variation with a p erio d of days
C LLOYD
K W WEST
Rutherford Appleton Lab oratory
Edward Street
Chilton Didcot
Ryde
OXON OX QX UK
Isle of Wight PO SH UK
cl ast star rl ac uk
kwest aladdin co uk
References
Bakos G A Tremko J Contr Astron Obs Skalnate Pleso
Batten A H Fletcher J M PASP
Eggen O J AJ
Jorissen A et al A A
Kholop ov P N et al General Catalogue of Variable Stars th edn Moscow
Little S J Little Marenin I R Bauer W H AJ
Ofek E O Shemmer O Gabzo O J BAA
Percy J R et al PASP
Percy J R Desjardins A Yu L Landis H J PASP
Vetesnik M IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
PHOTOMETRY OF THE ACTIVE PHASE OF AG Dra
h m s 0 00
The high velocity symbiotic star AG Dra : in
mid entered a new active phase which was characterized by a rapid brightening from
m m m
the quiescent magnitude of V : : in May to V : in July Mattei
Then the star faded back to minimum in November Similarly but unexp ectedly to
the previous active phases of and a secondary light maximum o ccurred
in July followed by a gradual decrease to quiescence Because of the uniqueness
of the event and for b eing AG Dra known to b e an intense sup ersoft X ray source a
campaign of multiwavelength observations was organized and optical photometry was
collected in co ordination with space IUE and ROSAT observations Greiner et al
Broad band BVRI photometry of AG Dra was obtained during July January
with the cm F telescop e at Greve Firenze and with the cm F
telescop e at Vallinfreda Roma Both telescop es are equipp ed with an SBIG ST CCD
detector The photometric accuracy was excellent during most nights the m s errors
m m m m
b eing of : in B : in V : in R and : in I As for the photometric sequence
we have used the secondary standards listed in Table whose photometric data were
obtained using stars from Landolt s catalogue
In addition three colour UBV photometry was obtained during December
February with a single channel photo electric photometer mounted at the Cassegrain
fo cus of the cm F telescop e of the National Astronomical Observatory Rozhen
m m m
The star BD having V : B V : and U B : Skopal Cho chol
m
was used as a comparison star The m s errors are not larger than : in U and
m
B and : in V The observational data are listed in Table
Figure gives the ve colour light curve of AG Dra during its active phase
The observations cover mainly the declining phases following the primary June and
secondary July light maxima No U band observations were obtained during the
maximum but that phase was also covered by the UBV observations of Skopal and
Cho chol The gure shows that AG Dra varied in all the colours but the amplitude
of the variation was larger and the decline steep er for the shorter wavelengths In
particular the variation of the U magnitude during the outburst when compared
to its value during quiescence indicates an increase by a factor larger than of the
radiation near the Balmer jump The variation was quite large also in B with a ux
increase with resp ect to quiescence of more than and magnitudes for the
and outbursts resp ectively It should b e noted that during the minimum phase i e b etween the two light maxima the U and B uxes were well ab ove their quiescent values
Table The BVRI photometric sequence
Star B V R I
h m s 0 00
a
m s 0 00
b
m s 0 00
c
m s 0 00
d
m s 0 00
e
m s 0 00
f
m s 0 00
g
Finally we remark that unexp ectedly during the light maxima AG Dra signi cantly
varied also in the I band which is near the maximum of the energy sp ectrum of the co ol
stellar comp onent
Figure The ve colour light curve of AG Dra from December to February
For comparison the AAVSO visual light curve day means Mattei is shown as
a dotted line
Table Photometric observations of AG Dra
Date JD n U B V R I
Dec
Apr
Jul
Aug
Aug
Oct
Feb
Mar
Aug
Aug
Sep
Sep
Sep
Oct
Oct
Oct
Oct
Oct
Oct
Nov
Nov
Dec
Jan
Feb
These results can b e interpreted in the light of a three sp ectral comp onent mo del of
AG Dra in which the red and near IR is dominated by the co ol star sp ectrum while the
blue and near UV radiation arises from the circumstellar nebula ionized by the radiation
of the hot star whose contribution to the near UV is thought to b e negligible
In this mo del the optical outbursts should b e asso ciated with the increase of the size of
the nebula which is the result of the increased ux of UV photons from the outbursting hot
source The U band excess of AG Dra is therefore due to the nebular Balmer continuum
which has largely increased during the outbursts The nebular emission app ears also
to contribute to the longer wavelengths and the amplitude of the variation at di erent
wavelengths can b e in principle used to determine the relative contribution of the nebular
and co ol star comp onents In this regard it is of particular interest that during the light
maxima AG Dra largely varied also in the I band nm This implies that at the
light maximum the nebular sp ectrum should have contributed to at least of the
red near IR radiation of AG Dra This contribution rises to more than in V and
to > in B We also argue that the contribution of the nebular emission to the red
might p ossibly b e not negligible also during the quiescent phase of AG Dra Therefore
some care should b e taken when using the VRI colours and the photospheric sp ectral
line depth as well for the determination of the red star s sp ectral type and luminosity class
M T and N T wish to thank R Zamanov for obtaining part of the observations
at NAO Rozhen Their work was supp orted in part by Bulgarian National Scienti c
Foundation grant under contract F with Ministry of Education Science and Tech
nology
Franco MONTAGNI
Maurizio MAESANO
Rob erto VIOTTI
Aldo ALTAMORE
Mima TOMOVA
Nikolai TOMOV
Istituto Astronomico
Universit aLa Sapienza
Via Lancisi I Roma
Istituto di Astro sica Spaziale
CNR Via Enrico Fermi
I Frascati Italy
and
National Astronomical Observatory
Rozhen P O Box
BG Smolyan Bulgaria
References
Greiner J Bickert K Luthardt R Viotti R Altamore A Gonzalez Riestra R
Stencel R E A A to b e submitted
Landolt A U AJ
Mattei J A AAVSO Observations
Skopal A Cho chol D IBVS No
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INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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May
HU ISSN
GT AQUARII NEW ELEMENTS
h m s 0
GT Aquarii SVS GSC : : was
m
rep orted by Kuro chkin as a variable star with a range of variation from : to
m d
: He found a p ossible pulsational variation with an uncertain p erio d of :
In view of this nding this star warrants some further investigation as it might b e a new
member of the AHB class of pulsating variables see Sandage Diethelm and Tammann
No other source of data is known to the author
During the season GT Aquarii was observed with the cm RC telescop e at
R Szafraniec Observatory in Metzerlen Switzerland by the author An un ltered ST
CCD camera was employed A total of observations in nights could b e secured
m
As comparison star GSC : lying very close to the variable was used
The comparison star showed no variation exceeding the accuracy of the photometry Due
to the proximity of the comparison star to GT Aqr as well as to the limited accuracy of
the photometry see b elow no correction for di erential extinction was allowed for
With the p erio d given by Kuro chkin our data do not yield a satisfactory light
d
curve A coarse p erio d nding algorithm leads to a most likely value of P : In
Figure the observations are presented folded with the elements
Max E
J D hel
Figure Un ltered CCD light curve of GT Aqr folded with the elements given ab ove
The rather large scatter seen in Figure is primarily due to two circumstances The
m m
star is ab out one magnitude fainter than given by Kuro chkin : : In addition
due to the negative declination of the variable the air mass was relatively large for an
observer at the latitude of Switzerland Therefore the signal to noise ratio of our CCD
frames was smaller than hop ed for Nevertheless we dare to state that some of the scatter
might b e caused by some intrinsic variability in the light curve
R DIETHELM
Rennweg
CH Ro dersdorf
Switzerland
References
Kuro chkin N E Perem Zv
Sandage A Diethelm R Tammann G A Astron Astrophys
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HU ISSN
CI AQUILAE
CI Aql AN was discovered due to a m mag outburst recorded on two
Heidelb erg plates in June Reinmuth It was much fainter on other pairs of
Heidelb erg plates taken b etween Reinmuth as well as Moscow plates
taken b etween Parenago This and the small outburst amplitude led
to the classi cation as a nova or dwarf nova with long cycle length Duerb eck
m m 00
Though there are three ob jects of with separation at the p osition of the
outburst ob ject the identi cation was p ossible due to the large scale of the discovery
plates as shown in Duerb eck A sp ectrum of the candidate ob ject taken in
the A range on May did not reveal the exp ected Balmer emission
lines Szkody and Howell and casts doubts on the identi cation Similarly two
sp ectra taken on May and August b etween A only showed
an absorption line sp ectrum Mennickent and Honeycutt The resolution of these
sp ectra was to o low to determine the sp ectral type of this ob ject but Na D and KI
A lines as well as the TiO bands suggested a K M type star
We observed sp ectroscopically all three ob jects the candidate star plus the two neigh
b ouring ob jects on two o ccasions in and with the m telescop e at the Calar
Alto Observatory On September the Cassegrain sp ectrograph equipp ed with a
RCA chip pixel size m was used with a A mm grating resulting in a
mean resolution of A FWHM in the A range The exp osure time was
min and min resp ectively starting at UT and On September
we used a A mm grating which allowed to cover the A with a resolution
of A FWHM The exp osure time was min starting at UT On June
the double sp ectrograph was used with A mm gratings for b oth the red and
blue arm which results in a resolution of slightly ab ove A FWHM and a coverage of
A and A The detectors were TEK mosaics with m
pixel size The exp osure time was min starting at UT Helium Argon sp ectra
were taken immediately after the science exp osures and the stars Feige September
and Wolf June were used for the ux calibration Standard MIDAS
pro cedures were applied for the reduction of the data
The two ob jects near the candidate ob ject of CI Aql are late type stars and do not
show any emission lines In contrast all three sp ectra of the candidate ob ject marked
in Duerb eck show the high excitation lines HeI I and NI I I CI I I in
emission see top and b ottom panel of Figure while Balmer emission lines are not
present
Based on observations collected at the German Spanish Astronomical Centre Calar Alto op erated by the MPI f ur Astronomie Heidelb erg jointly with the Spanish National Commission for Astronomy
Figure Medium resolution sp ectra of CI Aql from June top and middle panel
The letter K denotes the CaI I K band CaI I H enhances H while the symbol d
denotes a detector aw and atm stands for atmospheric absorption bands The
b ottom panel shows a blow up of the emission line regions at the same intensity scale
Sp ectra are ordered in time from top to b ottom Note that the OI line is
absent in June
Also we nd an emission line at A in the two September sp ectra which we
interpret as OI A Even at the highest sp ectral resolution these emission lines
only show a marginal double p eak structure which implies a velocity amplitude smaller
than km s We therefore conclude that the identi cation of CI Aql as given in
Duerb eck is correct and that CI Aql is presently in a state of low interaction
m
Recently Mennickent and Honeycutt rep orted the discovery of deep eclipses
d m
in the lightcurve of CI Aql with a p erio d of with an additional amplitude
secondary minimum shifted by in phase with resp ect to the eclipse The shap e of
the light curve is typical for a contact system of two comp onents with di ering surface
brightness and excludes the presence of a compact ob ject in CI Aql as would b e implied
by the previous nova or dwarf nova interpretation This is also supp orted by the shap e of
the sp ectrum which do es not show any blue comp onent down to A and no Balmer
lines in emission
At the given orbital p erio d and due to the weak mass dep endence of the semi ma jor
=
axis of the orbit a M M R a is of the order of R for a reasonable
range of masses M and M of the two comp onents This excludes the presence of a giant
as suggested in Mennickent and Honeycutt Thus the binary system in CI Aql has
to contain two stars with di erent surface brightness b eing either main sequence stars or
subgiants
All our sp ectra were taken in the phase interval i e around the secondary
minimum and thus are dominated by the bright comp onent The determination of the
sp ectral type of the bright comp onent app ears nevertheless to b e di cult We cannot use
the hydrogen Balmer lines b ecause they are a ected by the fainter late type comp onent
Similarly the NaI D A absorption blend is due to a sup erp osition of the con
tributions of b oth comp onents The presence of the Balmer absorption lines and of CaI I
H K on the one side and of CaI g and the G band on the other side con rm the existence
of two b o dies of di ering e ective temp erature
This combination of early and late type star might suggest some unusual RS CVn
type binary In addition to the sp ectroscopic observations we have therefore searched
Sonneb erg sky patrol plates taken mainly by Huth and Fuhrmann b etween
for additional eruptions of CI Aql The combined impression of CI Aql and the two
neighbouring stars mentioned at the b eginning is visible only on the very b est plates at
m
m transformed to Mt Wilson system using Selected Area and no further
pg
eruption was found
CI Aql has also b een in the eld of view of three ROSAT PSPC p ointings at di erent
o axis angles p erformed on Octob er April and September
Octob er but was not detected in any of these energy range keV The deep est
upp er limit on the X ray ux is cts s Dempsey et al have investigated
the soft X ray emission of nearby RS CVn systems using the ROSAT all sky survey
data Using their conversion factor of erg cm count we get an upp er limit X
ray luminosity of erg s D kp c This would imply a rather large extinction if
CI Aql is indeed a RS CVn system This is not inconsistent with the heavy interstellar
e ects in this direction Neckel and Klare but the lack of CaI I H and K emission
argues against a standard RS Canum Venaticorum type binary and so do es the contact type lightcurve
Summarising the lack of a blue continuum and the Balmer series as well as the shap e
of the orbital light curve of CI Aql clearly argue against a dwarf nova classi cation As
argued ab ove also a standard RS CVn nature seems unlikely With the present data we
cannot o er an alternative classi cation Since CI Aql is an eclipsing ob ject time resolved
sp ectroscopy is needed to allow the determination of more accurate sp ectral types of the
two comp onents as well as the velocity amplitudes
Acknowledgements The work of JG and WW is supp orted by funds of the German
Bundesministerium f ur Bildung Wissenschaft Forschung und Technik BMBF DARA
under contract No FKZ OR and S resp ectively
JOCHEN GREINER
JUAN M ALCALA
MPI f ur Extraterrestrische Physik
Giessenbachstr
D Garching Germany
WOLFGANG WENZEL
Hauptstr
D Sonneb erg Germany
References
Dempsey R C Linsky J L Fleming T A Schmitt J H M M ApJS
Duerb eck H W Space Sci Rev
Mennickent R E Honeycutt R K IBVS No
Neckel Th Klare G A A Suppl
Parenago P P Perem Zvesdy
Reinmuth K AN
Szkody P Howell S B ApJS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
PHOTOGRAPHIC AND CCD PHOTOMETRY OF V CEPHEI
The variability of V Cep was discovered by Gyulbudaghian and Sarkissian
comparing their photographic observations in NGC with the Palomar Observatory
m
Sky Survey charts They found the star to b e brighter in with more than in B
colour in comparison with the brightness in The following photometric observations
of V Cep Gyulbudaghian and Sarkissian Hakverdian and Gyulbudaghian
Shevchenko and Yakubov Pogosyants Semkov demonstrated changes
m
of brightness which are typical for T Tauri type stars with amplitude of ab out : in
B light The recent sp ectral observations of V Cep made in Miranda et al
con rmed that its sp ectrum is also of a T Tauri type star with a number of emission lines
and P Cygni pro le of H line
Table Photographic observations of V Cep in the p erio d December August
J D U B V J D U B V
mag mag mag mag mag mag
The present photometric data are a continuation of our investigation of V Cep which
has b een carried out since Semkov The UBV photographic observations were
made with the cm Schmidt telescop e of the National Astronomical Observa
tory Rozhen Bulgaria in the p erio d December August Table The B light
Figure Light curve in B light of V Cep during the p erio d July August
Semkov and this pap er
Figure Light curve of V Cep from all known observations
curve only from our observations during the p erio d July August is presented
in Figure The increase in B light has continued over the p erio d December
August The BVRI Kron CCD photometric observations were made with an SBIG
ST camera attached to the Rozhen m RCC telescop e Table The reductions to the
standard BVRI system were made according to Georgiev et al
Table BVRI Kron CCD photometry of V Cep
J D V B V V R V I
Using all known observations we comp osed the light curve in B pg band of V Cep
presented in Figure The mean value of the stellar magnitude for each year from all
photographic data is taken In Figure the crosses denote our photographic data Semkov
and this pap er the lled circles photographic data from Pogosyants the
squares photographic data from the Byurakan Schmidt telescop e Gyulbudaghian and
Sarkissian Hakverdian and Gyulbudaghian the lled triangle visual
estimation from the Palomar Observatory Sky Survey Prints the circles the mean photo
electric data from Shevchenko and Yakubov the triangles our CCD photometric
data From Figure the gradual increase of brightness of V Cep resembling the FU
Ori type star V Cyg Herbig can b e seen
This work was partly supp orted by grants F and F of the National
Science Fund of the Ministry of Education Science and Technologies Bulgaria
E H SEMKOV
Institute of Astronomy
Bulgarian Academy of Sciences
BG So a Bulgaria
e mail evgeni carina wfpa acad bg
References
Georgiev Ts Getov R Semkov E Mutafov A Todorova H Working group
on Wide eld imaging Newsletter
Gyulbudaghian A L Sarkissian R A Astr Tsirk No
Gyulbudaghian A L Sarkissian R A Astr Tsirk No
Hakverdian L G Gyulbudaghian A L Astr Tsirk No
Herbig G H ApJ
Miranda L F Eiroa C Fernandes M Gomez de Castro A I A A
Pogosyants A Yu IBVS No
Semkov E H IBVS No
Shevchenko V S Yakubov S D Azh
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
PHOTOELECTRIC MINIMA OF ECLIPSING BINARY SYSTEMS
We present minima observations of eclipsing binary systems not yet published
anywhere Most of the observed systems are apsidal motion stars or at least eccentric or
candidate stars selected from the listing of Heged us Some minima observations
are part of complete light curve coverages
One part of the observations was carried out at Piszk estet oMountain Observing Sta
tion of the Konkoly Observatory of the Hungarian Academy of Sciences with a in
f Cassegrain telescop e The photometer used was equipp ed with an unrefrigerated
EMI QB photomultiplier tub e and Schott UG for U BG GG for B and
GG for V lters This system is referred to as Pi in Table Another part of
the observations was made at Konkoly Observatory Budap est Szabads aghegy The
photometer was equipp ed with an unrefrigerated EMI B tub e Schott UG for U
BG GG for B and GG for V lters and mounted in the f Newtonian fo cus
of the in telescop e see eg Szeidl et al This system is marked as Bp in
Table Most of the measurements were made at Ba ja Astronomical Observatory with a
Starlight I photometer equipp ed with an unrefrigerated EMI A multiplier tub e and
Schott lters UG matching Johnsonian U GG BG matching B and OG
matching V mounted on the in Cassegrain f telescop e of JATE Szeged and
later on the in f Ritchey Chr etientelescop e Ba and Ba in Table resp ec
tively The system signed as Ba was describ ed by Heged us The XZ And and
CC Her minima were measured with an ST un ltered CCD camera installed on the
in RC telescop e
The observations were made b etween Reduction of the photo electric data
was made by standard pro cedures For the reduction of the CCD frames we used the
IMAGINE software All the minima times were computed using the parab olic tting
metho d The times are helio centric corrected ones
Table presents the derived minima times The content of the rst two columns is
self explaining In the third column the types of minima are marked I for primary and I I
for secondary ones while in the fourth column the number of individual data involved in
the parab olic t is given The columns from fth to seventh describ e the lters used the
rst three letters of the observers names and the co des of the instrumentation The last
column contains the comparisons and o ccasional check stars used identi ed by their BD
or GSC numbers This work was partly supp orted by the National Grants OTKA T
and OTKA F and the Lo cal Government of B acs KiskunCounty
Table
Star Min HJD Min Points Filter Obs s Instr Comp Check
type used name
XZ And I Bor Ba ST
I Bor Ba ST
V Aql II V Heg Pi BD
II B Heg Pi
II U Heg Pi
SS Ari I V Bor Pi BD BD
I B Bor Pi
II V Bor Pi
II B Bor Pi
II V Bor Bir Pi
II B Bor Bir Pi
AS Cam II V Heg Ba BD
II B Heg Ba
II V Heg Pi
II B Heg Pi
I V Bor Pi
I B Bor Pi
I U Bor Pi
II V Bor Ba
II B Bor Ba
I V Bor Ba
I B Bor Ba
RZ Cas II V Heg Bor Pi BD
II B Heg Bor Pi
I V Heg Bor Pi
I B Heg Bor Pi
II V Bor Ba
II B Bor Ba
II U Bor Ba
II V Bor Ba
II B Bor Ba
II U Bor Ba
I V Bir Ba
I B Bir Ba
I V Bor Ba
I B Bor Ba
I V Bir Ba
I B Bir Ba
TV Cas I V Bor Ba BD
I B Bor Ba
TW Cas I V Bir Ba BD
I B Bir Ba
I V Bir Ba
I B Bir Ba
VW Cep II V B Heg Ba BD
I V B Heg Ba
I V B Heg Ba
II V B Heg Ba
I V B Heg Ba
I V B Heg Ba
II V B Heg Ba
Table cont
Star Min HJD Min Points Filter Obs s Instr Comp Check
type used name
XX Cep I V Bir Pi BD
I B Bir Pi
EK Cep I V Heg Ba BD
I B Heg Ba
II V Heg Ba
II B Heg Ba
I V Heg Ba
I B Heg Ba
I V Heg Ba
I B Heg Ba
I B Heg Ba
I V Heg Ba
II V Heg Ba
I V Bor Ba
I B Bor Ba
GK Cep I V Bir Ba BD
I B Bir Ba
CG Cyg I V Par Bp BD BD
I B Par Bp
I U Par Bp
DK Cyg I V Par Bp BD
I B Par Bp
MR Cyg I B Bir Ba BD
I B Bor Pi
V Cyg I V Par Bp BD BD
I B Par Bp
V Cyg I V Heg Ba BD
I B Heg Ba
II B Heg Ba
II V Heg Ba
II B Heg Ba
TZ Dra I V Par Bp BD BD
I B Par Bp
I U Par Bp
RW Gem I V Bir Pi BD BD
AK Her I V Bor Pi BD
I B Bor Pi
I U Bor Pi
I V Bor Ba
I B Bor Ba
I V Bor Ba
I B Bor Ba
CC Her I Par Ba ST
DI Her II V Heg Ba BD
II B Heg Ba
II V Heg Bor Pi
II B Heg Bor Pi
II U Heg Bor Pi
HS Her II V Bor Ba BD
II B Bor Ba
I V Bor Ba
I B Bor Ba
Table cont
Star Min HJD Min Points Filter Obs s Instr Comp Check
type used name
AR Lac I V Bor Ba BD
I B Bor Ba
UV Leo I V Bor Ba BD
I B Bor Ba
I V Bir Ba
I B Bir Ba
FT Ori I V Heg Ba BD
I B Heg Ba
I V Bor Ba
I B Bor Ba
U Peg II V Bor Pi BD
II B Bor Pi
AG Per I V Heg Ba BD
II V Heg Ba
II B Heg Ba
I V Heg Ba
I B Heg Ba
I V Heg Ba
I B Heg Ba
II V Bor Ba
II B Bor Ba
I V Bor Ba
I B Bor Ba
IQ Per I V Bir Pi BD
I B Bir Pi
I V Bir Ba
I B Bir Ba
I U Bir Ba
b Per I V Bir Ba BD BD
TX UMa I V Bir Ba BD
I B Bir Ba
TIBOR HEGEDUS
IMRE BARNA BIRO
TAMAS BORKOVITS
1
ZSOLT PARAGI
Ba ja Astronomical Observatory of B acs Kiskun County Ba ja Szegedi ut P O Box H
Hungary eMail baja electra bajaobs hu
1
Present address FOMI Satellite Geo detic Observatory Budap est P O Box H Hungary
eMail paragizs moon sgo fomi hu
References
Heged us T IBVS No
Heged us T CDS Bul l
IMAGINE is a Trade Mark of Compuscop e Santa Barbara California
USA
Szeidl B Ol ah K Szabados L Barlai K Patk os L Comm Konkoly Obs
Budapest No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
PHOTOELECTRIC UBV OBSERVATIONS OF EG ANDROMEDAE
One of the patterns of the photometric variability of symbiotic binary systems is that
caused by the orbital motion Orbital variability is observed in the EG And system
d
consisting of an M I I I giant and a hot sub dwarf The p erio d is ab out and UBV
measurements have b een obtained practically at all orbital phases According to the
observations during the last years Hric et al Hric et al Skopal et
al two minima are present in the orbital photometric variations a primary
when the giant is towards the observer and a secondary one remote from the primary
approximately at the half orbital p erio d The data scattering is a sign of light uctuations
which b ecome most apparent in the area of the secondary minimum in U band Skopal
et al
Two di erent mo dels are prop osed for an explanation of the variations According to
the rst of them a re ection e ect has place in this system and the primary minimum
o ccurs when the unheated part of the giant s atmosphere is oriented towards the observer
Munari The hot comp onent of EG And however has a low luminosity Murset et
al which is insu cient see Belyakina for the heating of the giant Moreover
the Lyman luminosity is sp ent entirely for ionization of a p ortion of the wind of the
giant and according to the approach of Taylor and Seaquist the b oundary b etween
the ionized and the neutral p ortions is far away from its photosphere Skopal
has critically considered the p ossibility for re ection e ect and has shown that the light
variations of many symbiotic systems with low luminosity hot comp onents require an
explanation of principle
According to the second mo del Skopal et al Skopal a common envelope
having geometry of the equip otential surface containing the Lagrangian p oint L is re
sp onsible for the existence of the two minima in the orbital light curve In this mo del
however the giant s continuum which is dominant in the BV region Kenyon is
not taken into account This mo del meets also the next di culty In accordance with
Kenyon s colour colour diagnostic the UV continuum of EG And do es not in
dicate the presence of an optically thick accretion disk such as that formed as a result
of mass transfer via L That is why the view that the giant in this system do es not ll
its Ro che lob e and loses mass by means of stellar wind is widely accepted Oliversen et
al Vogel Vogel et al Vogel Munari Tomov The
existence of the envelope describ ed is not compatible with the existence of the giant s
wind exp ected in accordance with the theory of stellar evolution Having in mind the
di culties of the interpretation as well as the light uctuations p ointed we consider that
a large amount of observational data is required for comparison with the future mo dels
Table Di erential photometry of EG And against HD in magnitudes
Julian day V B U Julian day V B U
Figure Orbital UBV light variations of the EG And system
Here we present nineteen photo electric estimates in the three colour UBV system
obtained after November They were carried out with a single channel photo electric
photometer mounted at the Cassegrain fo cus of the m telescop e of the National
Astronomical Observatory Rozhen The data on JD have b een taken using
the similar telescop e and equipment of the Astronomical Observatory Belogradtchik The
star HD V B V has b een used as the comparison star The
data derived has b een pro cessed by means of a photo electric data software Kirov et
al using the reduction co e cients Zamanov private communication for b oth
atmospheric extinction and standard UBV system The di erential photometry m
m EG And m HD in the three colours is presented in Table
Our photometric data indicate orbital variations Figure The phases have b een
reckoned using the elements JD E where the zero phase is at the
min
ep o ch of the primary minimum Skopal et al The kind of the variations detected
as well as the amplitudes in the di erent bands are in agreement with the results of the
other observers Hric et al Skopal et al although the
phase range of the secondary minimum has not well b een covered
The authors wish to thank R Zamanov for obtaining a part of the observations This
work was supp orted in part by Bulgarian National Scienti c Foundation grant under
contract F with Ministry of Education Science and Technology
Nikolai TOMOV
Mima TOMOVA
NAO Rozhen
P O Box
BG Smolyan Bulgaria
e mail rozhen tu plovdiv bg
References
Belyakina T S Astro zika
Hric L Skopal A Urban Z Dap ergolas A Han zl D Isles J E Niarchos P
Papou sek J Pigulski A Veli c Z Contr Astr Obs Skalnat e Pleso
Hric L Skopal A Urban Z Kom z k R Luthardt R Papou sek J Han zl D
Blanco C Niarchos P Veli c Z Schweitzer E Contr Astr Obs Skalnat e
Pleso
Hric L Skopal A Cho chol D Kom zik R Urban Z Papou sek J Blanco C
Niarchos P Rovithis Livaniou H Rovithis P Chinarova L L Pikhun A I
Tsvetkova K Semkov E Veli c Z Schweitzer E Contr Astr Obs
Skalnat e Pleso
Kenyon S J in Davies R W Pringle J E Efstathiou G eds The symbiotic
stars Cambridge Univ Press Cambridge p
Kirov N K Antov A P Genkov V V Compt rend Acad bulg Sci
No
Munari U A A
Murset U Nussbaumer H Schmid H M Vogel M A A
Oliversen N A Anderson C M Stencel R E Slovak M H ApJ
Skopal A Contr Astr Obs Skalnat e Pleso
Skopal A Hric L Urban Z Pigulski A Blanco C Papou sek J Han zl D Agerer
F Niarchos P Rovithis Livaniou H Rovithis P Tsvetkova K Semkov E
Veli c Z Mich alek F Koma cka L Schweitzer E Korth S Contr Astr
Obs Skalnat e Pleso
Skopal A Vittone A Errico L Ap SS
Skopal A Hric L Cho chol D Kom zik R Urban Z Petrik K Niarchos P
Rovithis Livaniou H Rovithis P Oprescu G Dumitrescu A Ulyanikhina O
Schweitzer E Contr Astr Obs Skalnat e Pleso
Taylor A R Seaquist E R ApJ
Tomov N A MNRAS
Vogel M A A
Vogel M A A L
Vogel M Nussbaumer H Monier R A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
NEW VARIABLE STARS IN THE HERCULIS FIELD
This pap er continues the study b egun in my previous publication Antipin
Eight new variables were discovered in the eld centered on Her Var
This study is based on Moscow collection plates taken with the cm astrograph in
Crimea
Table contains co ordinates and GSC identi cations of new variables Co ordinates
for GSC stars were taken from the Guide Star Catalog for the rest of the stars they
00
were measured relative to neighbouring GSC stars The accuracy is ab out Table
presents for each star number of observations time interval JD type of variability
maximum and minimum brightness in B band M m or D Table contains light
elements ep o ch and p erio d for p erio dic variables Like in my previous publication the
standard near M Arp and Johnson Forbes and Dawson was used to obtain
the magnitudes of comparison stars Table Finding charts and phased light curves are
shown in Figures and resp ectively
Table Co ordinates and Identi cations of Variable Stars
Var GSC
h m s 0 00
Var
Var
Var
Var
Var
Var
Var
Var
Remarks on individual stars
Var EA classi cation is also p ossible for this variable Min I I
Var Min I I
Table Data on New Variable Stars
Var N JD Type Max Min M m or D
Var EB
Var RRab
Var RRab
Var RRab
Var EB
Var RRab
Var RRab
Var EA
Figure Finding charts
Figure Light curves
Table Light Elements
Var Max Min JD Period
d
Var
Var
Var
Var
Var
Var
Var
Var
Table Comparison Stars
Var a b c d e
Var
Var
Var
Var
Var
Var
Var
Var
S V ANTIPIN
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
References
Antipin S V Inf Bul l Var Stars No
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
Number
Konkoly Observatory
Budap est
May
HU ISSN
NEW VARIABLE STARS IN THE CORONAE BOREALIS FIELD
This pap er continues the study announced in IBVS No and deals with the search
and investigation of new variable stars using p ositive negative metho d Six new variables
were discovered in the eld centered on CrB Var This study is based
on Moscow collection plates taken with the cm astrograph in Crimea
The data in Tables and Figures are as in Antipin The photo electric
standard near V Her was used to obtain the magnitudes of comparison stars Shugarov
unpublished
Figure Finding charts
Figure Light curves
Figure Light curve of variable No
Remarks on individual stars
Var Blue on Palomar prints The star was seen on plates Nine outbursts were
observed Two kinds of outbursts with duration less than days Figure a and longer
than days Figure b were revealed Outbursts JD
Table Co ordinates and Identi cations of Variable Stars
Var GSC
h m s 0 00
Var
Var
Var
Var
Var
Var
Table Data on New Variable Stars
Var N JD Type Max Min M m
Var RRab
Var RRab
Var UG
Var RRab
Var RRab
Var RRab
Table Light Elements
Var Max JD Period
d
Var
Var
Var
Var
Var
Table Comparison Stars
Var a b c d e f g
Var
Var
Var
Var
Var
Var
S V ANTIPIN
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
Reference
Antipin S V Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
NEW VARIABLE STARS IN THE OPHIUCHI FIELD
This pap er continues the series of studies dealing with the search of new variables based
on Moscow collection of plates Nine new variables were discovered in the eld
centered on Oph Var
The variables were estimated on plates taken on JD The data on
the new variable stars are presented in Tables Finding charts and phased light curves
are shown in Figures and The standard sequence near NGC was used to obtain
the magnitudes of comparison stars Shugarov unpublished
Remarks on individual stars
Var Not present or very faint on the Palomar blue print The star was seen on
plates Three outbursts were observed Their duration is more than but less than
days Figure Outbursts JD
Var Periods ab out and days are p ossible Figure for Var Ep o ch
JD Red on Palomar prints The star is a strong enough IRAS source
Var Double Very close non coloured southwestern comp onent is present on Palo
mar prints but the image on our plates is single It is p ossible that the neighbouring star
was estimated in minima
Var RRb type
d
Var The cycle of variability is ab out Minimum brightness varies Figure
Table Co ordinates and Identi cations of Variable Stars
Var GSC IRAS
h m s 0 00
Var
Var
Var
Var
Var
Var
Var
Var
Var
Table Data on New Variable Stars
Var N Type Max Min M m Max JD Period
Var UG
d
Var M
Var SRa
Var RRab
Var RRab
Var SRa
Var M
Var RRab
Var SRb
Figure Finding charts
Figure Light curves
Figure Light curve of Var No
Figure Light curve of Var No
Table Comparison Stars
Var a b c d e f g
Var
Var
Var
Var
Var
Var
Var
Var
Var
S V ANTIPIN
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
NINE NEW VARIABLES IN THE OPHIUCHI FIELD
This pap er continues the study b egun in my previous publication Antipin
Nine more new variables were discovered in the eld centered on Oph Var
This study is based on Moscow collection plates taken with the cm astrograph
in Crimea
The data in Tables contain information on the new variables Figures and the
photometric standard are as in the previous pap er
This series of four studies was supp orted in part by the Russian Foundation for Basic
Research through grant No Thanks are due to Dr N N Samus for his
attention to this investigation to N A Gorynya and M I Antipina for their assistance
during the preparation of the gures and to S Yu Shugarov for p ermission to use his
unpublished standard sequences
Figure Finding charts
Figure Light curves
Figure Light curve of Var No
Remarks on individual stars
Var Min II
Var Red fast enough irregular variable
Var Red on Palomar prints The fragment of the light curve is given in Figure
Var Very unstable light curve Maximum brightness varies The identi cation
with IRAS catalog is uncertain The di erence b etween co ordinates from IRAS and those
00
based on GSC stars is ab out
Table Co ordinates and Identi cations of Variable Stars
Var GSC IRAS
h m s 0 00
Var
Var
Var
Var
Var
Var
Var
Var
Var
Table Data on New Variable Stars
Var N JD Type Max Min M m or D
Var EA
Var RRab
Var RRab
Var EB
Var Isb
Var Lb
Var RRab
Var RRab
Var M
Table Light Elements
Var Max Min JD Period
d
Var
Var
Var
Var
Var
Var
Var
Table Comparison Stars
Var a b c d e
Var
Var
Var
Var
Var
Var
Var
Var
Var
S V ANTIPIN
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
Reference
Antipin S V Inf Bul l Var Stars No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
THE SPECTRUM OF FG SAGITTAE IN
The temp oral b ehaviour of the remarkable variable star FG Sge has received much
attention in the recent years due to its unusual activity after its sudden fading in
Papou sek We have routinely obtained some sp ectra of FG Sge every year trying
to detect p ossible changes in its sp ectrum All our sp ectra from and onwards were
obtained with the echelle sp ectrograph Lynx of the m telescop e of the Sp ecial As
trophysical Observatory Panchuk et al These sp ectra cover the sp ectral region
In the sp ectra obtained in just few weeks b efore the dimming started we identi ed
C Swan bands clearly indicating that FG Sge has b ecome a carb on star Kipp er Kipp er
Iijima Strafella have found C bands in low resolution sp ectra taken much
earlier in In our sp ectra obtained in the C bands were still present and in
NaI D doublet a P Cygni type emission has app eared This allowed us to estimate some
parameters of the expanding shell around FG Sge Kipp er et al The intensities
of emission comp onents of the doublet changed in on the time scale of weeks There
were no low excitation heavy element lines in emission which however were visible in
the sp ectra obtained near the deep minimum in by Smith et al
In FG Sge changed in brightness in a quite sp oradic manner from V to
V according to the data by Hungarian Astronomical Asso ciation Variable Star
Section During the sp ectral observations on and August FG Sge was very
faint HAA VSS data V according to Variable Stars Observers League
00
of Japan V and therefore erroneously the visual companion apart from
FG Sge was actually observed This is probably the rst high resolution sp ectrum of the
companion ever obtained The sp ectrum turned out to corresp ond to a quite normal giant
with the sp ectral type around K For more detailed classi cation some blue classi cation
sp ectra should b e obtained Adopting CI Herbig Boyarchuk one could
estimate with this sp ectral type K I I I the distance of the companion kp c close or
larger to that of FG Sge The radial velocity of the companion is km s that of
FG Sge itself is km s The emission lines of OI NI I and H originated in the
planetary nebula He surrounding FG Sge are clearly visible in the sp ectrum of the
companion
The sp ectrum of FG Sge itself was obtained on December when the star was
relatively bright V From February a new very steep fading of FG Sge
started again Mattei There are no drastic changes in the absorption sp ectrum
compared with the sp ectra obtained in and The C Swan bands are still
present and the C O abundance ratio is around This value corresp onds to the case
when the solar O abundance and the e ective temp erature of K are assumed for
mo delling and sp ectrum synthesis Like a year b efore the only emission lines are the P
Cygni type emission comp onents of NaI D lines
Figure The NaI D lines in the sp ectrum of FG Sge obtained on Dec The p ositions of
zero velocity photospheric lines are indicated by asterisks Some of the lines from the earlier line lists
Kipp er Kipp er Wallerstein are indicated with their identi cations or noted as
unidenti ed u i The relative radial velocities of comp onents are indicated with arrows
As in the most drastic changes app eared in the pro les of NaI D doublet shown in
Figure The wavelength scale in this Figure takes into account the mean radial velocity
V km s found for the sp ectral region The continuum level was
rad
estimated for the same region We exp ect the error in V to b e less than km s
rad
The sharp comp onents at nearly km s were also observed in and
and corresp ond most probably to the interstellar gas In the sp ectrum of the companion
these lines are not fully resolved causing only some extra absorption in the red wings
of the doublet These comp onents have the V relative to the Sun ab out km s
rad
According to Langer et al there is an interstellar cloud in the line of sight with
V km s Taking into account the p ossible errors in radial velocities it is obvious
rad
that the IS lines corresp ond to that cloud
The absorption comp onents at km s could corresp ond to expanding higher
levels of the photosphere but the apparent blueward shift could well b e the result of the
blending with the emission part of the pro le
The circumstellar absorption comp onents at and km s corresp ond to the
shells ejected at di erent times The complicated structure of the doublet do es not allow
the quantitative analysis we p erformed for sp ectrum
V G KLOCHKOVA
T KIPPER
Sp ecial Astrophysical
Tartu Observatory
Observatory RAS
T oravere EE
Nizhnij Arkhyz
Estonia
Russia
References
Herbig G Boyarchuk A ApJ
Iijima T Strafella F IBVS No
Kipp er T Kipp er M A A
Kipp er T Kipp er M Klo chkova V G A A L
Langer G Kraft R P Anderson K S ApJ
Mattei J A AAVSO News Flash
Panchuk V E Klo chkova V G Galasutdinov G A Ryadchenko V P Chentsov E L
AZh Lett
Papou sek J IAU Circ No
Smith V V Gonzalez G Lambert D L Rao N K Poster at nd Intern Coll
on Hydrogen de cient Stars
Wallerstein G ApJS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
IMPROVED POSITIONS OF VARIABLE STARS IN ARA I
As a part of a program conducted to revise and improve the co ordinates of southern
variable and susp ected variable stars accurate p ositions of con rmed variables in Ara are
herein presented
The metho ds general description as well as goals of this pro ject can b e found in
L opez and Girard For some of the stars variables and susp ected variables so far
rep orted including the ones in this note we have improved their p ositions by measuring
the rst ep o ch plates of the Yale San Juan astrometric survey of the southern hemisphere
see L opez and Girard L opez L opez and Mira In some other cases the
program stars have b een identi ed in the Hubble Space Telescope Guide Star Catalogue
GSC L opez L opez and L epez
Table contains the newly determined p ositions For each star we have listed the
name of the variable the new RA and Dec equinox B ep o ch b etween
00
and and average standard error of : for b oth co ordinates and the di erences
b etween our new p ositions and those quoted in the GCVS IV in the sense new p ositions
minus GCVS IV co ordinates
Considering the stars in Table plus the already published in di erent notes
of this program the total number of variable stars for which we have b een able to improve
their co ordinates is now
Carlos E LOPEZ
Hector S LEPEZ
Felix Aguilar and Yale Southern Obs
Benavidez o este
Chimbas
San Juan ARGENTINA
E mail celop ez unsjfa edu ar
References
L opez C E Inf Bul l Var Stars No
L opez C E Inf Bul l Var Stars No
L opez C E Girard T M Publ Astron Soc of the Paci c
L opez C E and L epez H S Inf Bul l Var Stars No
L opez C E and Mira H Inf Bul l Var Stars No
Table Improved Positions of Variable Stars in Ara
Star RA DEC RA DEC
0 00 0
h m s m
T
U
W
X
Y
RU
RW
RX
RY
SW
SX
SY
SZ
UW
UX
UY
UZ
VV
VW
VZ
WW
WY
WZ
XX
XY
YY
YZ
AA
AB
Table cont
Star RA DEC RA DEC
0 00 0
h m s m
AC
AD
AF
AH
AT
AX
BF
BW
BY
BZ
CC
CF
CH
CL
CM
CN
CO
CP
CQ
CS
CT
CU
CV
CX
CY
DE
DF
DG
DI
DK
DL
Table cont
Star RA DEC RA DEC
0 00 0
h m s m
DM
DO
DP
DS
DT
DW
DX
DZ
EE
EF
EG
EI
EK
EL
EM
EN
EO
EQ
ES
ET
EU
EW
EX
EY
FF
FI
FL
FM
FN
FO
FP
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
May
HU ISSN
DISCOVERY OF MIN OSCILLATIONS IN THE Ap Sr EuCr STAR
HD
Using the Str omgrenphotometry of Martinez as a guide we have b een searching
for rapidly oscillating Ap roAp stars in the southern hemisphere The roAp stars are
co ol magnetic chemically p eculiar A type stars typically classi ed as Ap SrCrEu that
pulsate with p erio ds in the range minutes and Johnson B semi amplitudes
mag There are currently accepted members in the class Martinez This Bulletin
announces the discovery of minute oscillations in the candidate roAp star HD
Although this star is indisputably variable it is not clear that it is a roAp star as we
discuss b elow Figure
HD is classi ed as Ap Sr EuCr by Houk who remarks weak case un
00
detected visual double P D mags Martinez measured the
Str omgrenindices to b e V b y m c and
1 1
The calculated dereddened metallicity and luminosity indices are m and
1
c which indicate strong metallicity and heavy line blo cking in the Str omgren
1
v band characteristics which we asso ciate with roAp stars
On the night of March JD we observed HD for hr
using the Radcli e People s Photometer attached to the m telescop e of the South
African Astronomical Observatory in Sutherland The data were acquired as continuous
s integrations in Johnson B light A half hour oscillation was evident at the telescop e
as con rmed by subsequent analysis of the light curve The data were corrected for
coincidence counting losses sky background and extinction Some low frequency
Hz sky transparency variations were then removed and the data were binned to
1
hour p ortion of this light curve and the discrete s integrations Figure shows a
2
Fourier transform of the full light curve The tallest p eak in the Fourier transform is at
Hz P min and has an amplitude of mmag These oscillations have b een
con rmed by subsequent observations acquired using the Mo dular Photometer attached
to the SAAO s m telescop e Comparison of the available light curves for this star
indicates that the amplitude is mo dulated This may b e caused by rotation and or by
b eating of two or more indep endent pulsation frequencies
The interpretation of the oscillations in HD is not straightforward A p erio d of
min is rather long for a roAp star but also rather short for a Sct star It would b e
interesting to demonstrate the existence of Sct type oscillations in an Ap star but it is
not clear that Houk s Ap Sr EuCr classi cation is correct The m index suggests a high
1
00
metallicity indicative of Ap stars Given the separation and the apparent brightness
of this double the p ossibility that this system comprises a chemically normal star and
a magnetic chemically p eculiar star cannot b e excluded Since the stars comprising
this double have such a small magnitude di erence b oth stars are probably inside the
instability strip making it di cult to establish which is the variable
I acknowledge a fruitful discussion with Don Kurtz and thank him for his helpful com
ments
PETER MARTINEZ
Department of Astronomy
University of Cap e Town
Rondeb osch
South Africa
email p eter uctvms uct ac za
References
Martinez P Ph D Dissertation University of Cap e Town
Houk N Michigan Spectral Catalogue of Two Dimensional Spectral Types for the
HD Stars Volume Department of Astronomy University of Michigan Ann Arb or Michigan
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
June
HU ISSN
PHOTOMETRIC VARIABILITY OF THE BOOTIS STAR HD
HD was classi ed by Gray Corbally as a Bo otis star with p eculiar
8
hydrogen line pro les With an age of y r Iliev Barzova it is one of the
youngest Bo otis stars The p eculiar nature of this group leads to a severe uncertainty
to establish their lo cation in the Hertzsprung Russell diagram The imp ortance of dis
covering pulsation among Bo otis stars was discussed by Weiss et al As part
of our global survey for pulsating Bo otis stars we observed HD for two nights in
January with the Lowell m telescop e at CTIO observer M Gelbmann Table
lists the observing log The light curves of the rst night are plotted in Figure The
variation of HD compared to the measurements of the comparison star is clearly
visible The amplitude sp ectrum of the di erential data in Str omgren b and the sp ectral
window derived by a standard Fourier technique is shown in Figure The highest p eak
app ears at c d which corresp onds to a p erio d of minutes and with an amplitude
of ab out mmag This is the second star we found to b e variable with such a high frequency Kuschnig et al
4.54
4.52 HD 30422 mag (b) 5.82
5.80 HD 30182
0.05 0.10 0.15 0.20
JD 2449697.5+
Figure Light curve for HD and the comparison star HD in Str omgren b
for the second night
0.012
0.010
0.008
-40 -20 0 20 40 0.006 f=47.3 d-1
semi-amplitude (b) 0.004
0.002
0.000
0 20 40 60 80 100
frequency [d-1]
Figure Amplitude sp ectrum and sp ectral window for the di erential data of HD
and HD in Str omgren b for b oth nights
Table Observing log for the program and comparison star
Star Durchm JD hours m Sp ec
V
HD CD Bo o
HD CD K I I I
Acknowledgement This research was done within the working group Asteroseismology
AMS Computing resources and nancial supp ort for this international collab oration were
provided by the Fonds zur F orderung der wissenschaftlichen Forschung pro ject S
AST and the Ho chschuljubil aumsstiftung der Stadt Wien Bo otis Sterne This re
search has made use of the Simbad database op erated at CDS Strasb ourg France
R KUSCHNIG
M GELBMANN
E PAUNZEN
W W WEISS
Institut f ur Astronomie
T urkenschanzstra e
A Wien Austria
e mail paunzen astro ast univie ac at
References
Gray R O Corbally C J AJ
Iliev I K Barzova I S A A
Kuschnig R Paunzen E Weiss W W IBVS No
Weiss W W Paunzen E Kuschnig R Schneider H A A
ERRATUM
In Table of the IBVS No several cross identi cations have b een erroneously given
The correct version of the Table is given b elow
Table Program and comparison stars this comparison star is used for the gure
Star Durchm JD hours m Sp ec Upp er level b
V
HD CD Bo o
HD CD F IV
HD BD Bo o
HD BD A IV
HD BD B I I I
HD CD Bo o
HD CD F V
HD CD A V
HD CP Bo o
HD CP B V
HD CD Bo o
HD CD F V
HD CD A V
HD BD Bo o
HD BD F I I I
HD BD A IV
HD CP Bo o
HD CP Am
HD CD Bo o
HD CD Bo o
HD CD A V
HD BD Bo o
HD BD F
HD BD F V
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
June
HU ISSN
DISCOVERY OF THE NEW RR LYRAE STAR GSC
During p ointing tests of our telescop e it was noticed that the star GSC at
h m s 0 00
a p osition of RA Dec V Jenkner et al had
J J
changed in brightness
The automated m telescop e Cousins R lter and CCD camera of the Climenhaga
Observatory of the University of Victoria Robb and Honkanen were used to make
photometric observations of this star The frames were bias subtracted and at elded in
the usual manner using IRAF The magnitudes were found from ap erture photometry
using the PHOT package The x y pixel co ordinates of each star for photometry were
found from insp ection of a few frames and these p ositions were used as starting p oints
for the Gaussian centering option which precisely centered the arc second ap erture on
each star for each frame
From the Hubble Space Telescope Guide Star Catalog Jenkner et al the co or
dinates J and magnitudes of the stars observed are given Table GSC
was chosen as the comparison star and all di erential magnitudes are given in the sense
other star minus comparison star The standard deviation of the di erence b etween the
m m
brightest check star and the comparison star during a night ranged from : to :
For each check star the mean and standard deviation of the seven nightly mean di er
ential R magnitudes are given in Table The standard deviations give us estimate of
the precision of the di erential variable star minus comparison star measurements Due
to the small eld of view rst order di erential 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 the R magnitude to a standard system
Photometric observations were made March to May UT Brightness
variations were evident b oth during a night and from night to night On the longest
night the whole ascending branch was observed and when combined with the slop e of the
d
descending branch we nd that the p erio d must b e longer than : Two times of maxi
mum light were found by the metho d of Kwee and van Woerden to b e
and This metho d is not appropriate for asymmetrical extrema unless the
range of data searched is the same for all nights In this case the range was days
The uncertainty in the times of maximum is estimated to b e : days The times of
maximum light place strong limits on what the p erio d could b e since an integer number
of cycles must o ccur in the interval Plots of the light curve at all allowed p erio ds from
d d
: to : days were insp ected The only plot to give a reasonable light curve was the
one with the ephemeris
HJD of Maxima E
1
IRAF is distributed by National Optical Astronomy Observatories which is op erated by the Asso ciation of Universities for Research in Astronomy Inc under contract to the National Science Foundation
Table Stars Observed
GSC Number Right Ascension Declination GSC Mag Di erential
J J R Magnitude
h m s 0 00
h m s 0 00
h m s 0 00
: :
h m s 0 00
: :
h m s 0 00
: :
h m s 0 00
: :
Figure Di erential R data light curve of GSC
A plot of the di erential R magnitudes phased at this p erio d is shown in Figure
with di erent symbols for each of the di erent nights Despite some nights of p o or
quality the standard deviations in Table show that the exp ected errors from night to
night are far smaller than the di erences seen in the light curve Note that the height of
the maximum is not the same while the minima are the same brightness
A sp ectrum of GSC was obtained using the Dominion Astrophysical Observa
tory m telescop e and sp ectrograph on March UT with a disp ersion
of approximately Angstroms p er mm In Figure this sp ectrum is shown b elow a
sp ectrum of RR Lyrae taken with the same instrument con guration The similarity is
obvious From the sp ectrum and the shap e of the light curve we conclude that this star
is an RR Lyrae of sub type ab
Figure Sp ectrum of GSC b elow and RR Lyrae ab ove
M D GLADDERS
R M ROBB
Visiting Astronomers at the
Dominion Astrophysical Observatory
and the
Climenhaga Observatory
Dept of Physics and Astronomy
University of Victoria
Victoria BC CANADA V W P
Internet gladders cita utoronto ca
Internet robb uvphys phys uvic ca
References
Jenkner H Lasker B Sturch C McLean B Shara M Russell J AJ
Kwee K K and Van Woerden H Bul l Astr Inst Neth
Robb R M and Honkanen N N in A S P Conf Ser Automated Telescopes
for Photometry and Imaging ed Adelman Dukes and Adelman
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
June
HU ISSN
NONVARIABILITY AMONG BOOTIS STARS I I I
CTIO AND McDONALD DATA
This is the third and last pap er on constant Bo otis stars from our survey Paunzen et
al and Kuschnig et al Up to now we have presented Bo otis stars with
an upp er limit for nonvariability In this pap er we add new Bo otis stars
The observations were p erformed at CTIO in April observer E Paunzen with
the m Lowell telescop e and at McDonald Observatory in August observer G
Handler with the m telescop e The data were corrected for the sky background
deadtime and extinction The upp er limit for nonvariability was derived by a standard
Fourier technique using the di erential data of the program and one comparison star the
latter marked with an asterisk in Table Table lists the results for b oth observing
runs
Table Program and comparison stars
Star Site Observer JD hours m Sp ec Upp er limit b
V
HD CTIO EP Bo o
HD A V
HD McD GH Bo o
HD A IV
HD McD GH Bo o
HD A V
HD B V
HD CTIO EP Bo o
HD F V
HD McD GH Bo o
HD A
HD A
HD McD GH Bo o
HD B
We also present data on the prototype of this group Bo otis HD itself The
upp er level of nonvariability is quite high mmag in Str omgren b due to the rather p o or
quality of b oth nights Recent sp ectroscopy indicates nonradial pulsation with a very low
amplitude Bohlender
From the results of all three pap ers we conclude a typically achieved limit for nonva
riability in the relevant frequency range to c d of ab out mmag in Str omgren b
Our survey is still ongoing Nevertheless we are preparing a detailed analysis on the
pulsation b ehaviour of Bo otis stars
Acknowledgement This research was done within the working group Asteroseismology
AMS Computing resources and nancial supp ort for this international collab oration were
provided by the Fonds zur F orderung der wissenschaftlichen Forschung pro ject S
AST and the Ho chschuljubil aumsstiftung der Stadt Wien Bo otis Sterne GH ac
knowledges partial nancial supp ort by the Austrian Zentrum f ur Auslandsstudien This
research has made use of the Simbad database op erated at CDS Strasb ourg France
E PAUNZEN
G HANDLER
W W WEISS
Institut f ur Astronomie T urkenschanzstra e A Wien Austria
e mail paunzen astro ast univie ac at
e mail handler astro ast univie ac at
References
Bohlender D A private communication
Kuschnig R Gelbmann M Paunzen E Weiss W W IBVS No
Paunzen E Weiss W W Kuschnig R IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
HBV A NEW VARIABLE STAR IN HERCULES
An emission line star near the PN Hu PK in Hercules denoted as HBV
was found to b e a long p erio d variable Mira Ceti type during photographic observations
of the Stellar ring No The Schmidt camera f cm of the Hamburg
h m s
Observatory in Bergedorf was used The p osition of HBV is :
0 00
:
Altogether direct Schmidt plates were taken in V Ko dak a D GG b etween
May and June Seven comparison stars are shown together with the variable
in Figure their V magnitudes measured at least on plates are presented in Table
the accuracy of these magnitudes varies b etween mag and mag with the
exception of the star No Individual measurements of HBV are given in Table
with the accuracy of ab out mag The plates were measured with the Ha ner iris
photometer Ha ner The star varies b etween and mag Assuming in
the rst approximation a sine like light curve we have derived p erio d of days and
an amplitude V mag V b etween and mag
The photo electric sequence of Isserstedt and Schmidt Kaler was exp osed on the
plates with nearly the same distance from the centre as in the case of the variable
Table Comparison stars Table Brightness of HBV
Comparison V n Plate JD V
star mag No GS mag
m m
: :
Figure Identi cation chart of the variable and the comparison stars
The sp ectral characteristics of the variable star are typical for a long p erio d variable
of the sp ectral type Me there are Schmidt sp ectral plates in the region A
which show a medium strong continuum and the emission lines H H and probably H
as well as TiO bands and A
Acknowledgements I am grateful to U Haug for his contribution to the discovery of
the variable esp ecially for having taken some plates which b elong to our observations
concerning the stellar ring No
L KOHOUTEK
Hamburger Sternwarte
Go jenbergsweg
D Hamburg
Germany
e mail lkohoutek hs uni hamburg de
References
Ha ner H Ver o Univ Sternw G ottingen
Isserstedt J Schmidt Kaler T A A
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
CCD PHOTOMETRY OF CN Tau V Lyr V Cyg AND GS Lyr
CCD observations of the variable stars CN Tau V Lyr V Cyg and GS Lyr using
the CCD Transit Instrument CTI and Capilla Peak Observatory are rep orted The CTI
is a stationary meridian p ointing optical telescop e that images a narrow strip of the sky
at all right ascensions McGraw et al Wetterer The meter
f telescop e is rigidly mounted to p oint at a single declination and relies on the Earth s
rotation to bring di erent parts of the sky into view The photometry of a selection
of nonvariable stars distributed throughout the survey area and acquired during several
nights throughout the year were used to calibrate the data from all nights of observations
Cawson et al Wetterer All stars in the CTI survey are calibrated in this
consistent instrumental magnitude system and so any variable star within the CTI survey
will have many nearby calibrated comparison stars To establish the conversion b etween
instrumental and standard magnitudes a number of stars within the CTI survey were
also calibrated to the standard Johnson magnitude system McGraw et al
The photometric data for all stars within the survey area were analyzed to discover
RR Lyrae variable stars Wetterer et al In this search we excluded the p ortion of
the CTI survey area near the Galactic plane due to the excessive and unknown reddening
caused by dust in the Galactic disk Three stars previously classi ed as RR Lyrae stars
CN Tau V Lyr and V Cyg within the excluded region were observed by the CTI
We included these stars in subsequent CCD observations with Capilla Peak Observatory s
cm telescop e Laubscher et al Despite b eing listed as a slow irregular type
variable star we also included GS Lyr in the observation program b ecause up on initial
insp ection its light curve had RR Lyrae characteristics Table lists the name right
ascension and declination ep o ch the number of CTI and the number of Capilla
Peak CAP observations through the V lter for each star
Table summarizes the results After the star s name the next ve columns list
the maximum minimum and ux averaged standard V magnitudes the amplitude of
variation in V V and the B V at minimum light Wetterer et al details
the transformation from instrumental to standard magnitudes and how the ux averaged
magnitude was calculated The nal four columns list the rise time in fraction of a
p erio d m M the p erio d in days found using a standard p erio d nding algorithm
the helio centric Julian Date of maximum light minus days and the type of
variability for each star Finder charts light curves and photometry for these stars can
b e found in Wetterer
Table Variable Stars
Star CTI CAP
h m s 0 00
CN Tau
GS Lyr
V Lyr
V Cyg
Table Photometry results
Star V V V V B V m M Period HJD Type
M ax M in M ean
CN Tau C s
GS Lyr L
V Lyr RRab
V Cyg RRc
Table V observations of GS Lyr
HJD V HJD V HJD V HJD V
The calculated p erio d for CN Tau is signi cantly di erent than that listed in the
General Catalog of Variable Stars GCVS Kholop ov et al The GCVS p erio d
turns out to b e a sidereal day alias of the true p erio d In light of the longer p erio d
calculated from CTI and Capilla Peak data and the star s lo cation near the Galactic
plane it is likely that CN Tau is actually a short p erio d Cepheid instead of an RR Lyrae
variable star
The calculated p erio d for V Lyr using the CTI and Capilla Peak data is nearly
identical s shorter to that listed in the GCVS The current classi cation as an RR
Lyrae type ab is con rmed Due to the image scale V Lyr was combined with two
other fainter stars during CTI photometry The Capilla Peak data was used to estimate
the magnitudes of these stars V and V The standard
magnitudes in Table re ect the fact that the contribution from these fainter stars were
removed
Table B observations of GS Lyr
HJD B HJD B HJD B HJD B
12.4
12.6
12.8
13 V Magnitude
13.2
13.4
7500 8000 8500 9000 9500
Julian Date (minus 2440000)
Figure V magnitude of GS Lyr versus HJD
The calculated p erio d for V Cyg using the CTI and Capilla Peak data is approx
imately seconds longer than that listed in the GCVS The light curve has a slight
asymmetry and with its current p erio d and color a classi cation as an RR Lyrae type c
seems reasonable Again due to the image scale V Cyg was combined with two other
stars during CTI photometry As in the previous case the Capilla Peak data was used
to estimate the magnitudes of these stars V and V
which we to ok into account when calculating the standard magnitudes in Table
With the additional observations at Capilla Peak it b ecame quickly apparent that the
RR Lyrae like light curve for GS Lyr was due to the limited number of CTI observations
and the sidereal day aliasing present in the CTI data Further observations however
were conducted in an attempt to obtain an accurate classi cation Tables and list the
helio centric Julian date minus days and the instrumental V and B magnitudes
resp ectively for all observations of GS Lyr
Data b efore JD is from the CTI while data after is from Capilla Peak The
Capilla Peak data has b een transformed to CTI instrumental magnitudes The average
error in the CTI V magnitude is while the average error in the Capilla Peak V
magnitude is The average error for b oth the CTI and Capilla Peak B magnitudes
is Figure plots the instrumental V magnitude as a function of time for all obser
m
vations The instrumental B V resulting in standard V magnitudes fainter
than the instrumental magnitudes GS Lyr was previously classi ed as a slow irregular
variable in the GCVS This classi cation remains appropriate in view of the fact that
variations to ok place over several days and no p erio dicity could b e found in the present
data
RANDY GRASHUIS
ROBERT KUNKLE and
CHARLES WETTERER
KIRSTEN BOUDREAU
Department of Physics
Institute for Astrophysics
United States Air Force Academy
University of New Mexico
Fairchild Drive Suite A
Yale Blvd NE
US Air Force Academy CO
Albuquerque NM
USA
USA
References
Cawson M G M McGraw J T Keane M J SPIE Proc
Kholop ov P N General Catalogue of Variable Stars th edition Nauka Moscow
Laubscher B Gregory S Bauer T Zeilik M Burns J PASP
McGraw J T Angel J R P Sargent T A SPIE Proc
McGraw J T Sto ckman H S Angel J R P Epps H Williams J T SPIE Proc
McGraw J T Cawson M G M Keane M J SPIE Proc
McGraw J T Hess T R Green E M Bridges C T Benedict G F BAAS
No
Wetterer C J PhD dissertation University of New Mexico
Wetterer C J McGraw J T Hess T R Grashuis R AJ to b e published
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
IDENTIFICATION OF DAHLMARK VARIABLES
In his latest list of new variable stars Dahlmark suggested a number of iden
ti cations with known variable stars In addition to Dahlmark s prop osed identi cations
LD V Cygni or V Cygni LD FK Lacertae and LD NSV
the current author susp ected that LD NSV and that LD HL Lacertae
To con rm these p ossible identi cations comparisons were made b etween Dahlmark s
nding charts and the original nding charts for the known variables V Cygni
Ho meister a V Cygni Ho meister FK Lacertae Ho meister b
HL Lacertae Ho meister and NSV Ho meister There was no nd
ing chart given for NSV by Ross
The nder chart comparisons show that the identi cation of LD with FK Lacertae
is incorrect but that the other four LD ob jects can b e identi ed with known variable
stars noting that LD V Cygni
Accurate co ordinates and identi cations from the Guide Star Catalogue GSC are
given in Table Discrepancies with GCVS p ositions are noted Positions without GSC
identi cations were measured on the Digital Sky Survey The number of comparison stars
used in the reduction is given in the table the internal r m s residual of the comparison
00
stars was : for all the reductions Although no con rming chart is available the newly
determined p osition for LD is in excellent agreement with the GCVS p osition for NSV
Gareth V WILLIAMS
Harvard Smithsonian Center for
Astrophysics
Garden Street
Cambridge MA
U S A
E mail gwilliams cfa harvard edu
References
Dahlmark L I B V S No
Ho meister C a M V S No
Ho meister C b M V S No
Ho meister C Astron Nachr
Ho meister C Astron Nachr
Ho meister C Astron Nachr
Kholop ov P N et al General Catalogue of Variable Stars th edition
Moscow Nauka Publishing House
Ross F E Astron J
Table Accurate co ordinates and GSC identi cations
Ob ject R A Decl GSC id LD id Note
h m s 0 00
V Cyg : :
V Cyg LD
LD
FK Lac
HL Lac LD
NSV LD
LD
Note
s
GCVS R A in error by
s
GCVS R A in error by
s
GSC comparison stars GCVS R A in error by
s 0
GSC comparison stars GCVS R A in error by Decl by
h m s 0
GSC comparison stars J GCVS p osition R A Decl :
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
PHOTOMETRY OF ORIONIS OCTOBER TO APRIL
We present another two year summary of V band photometry of Orionis Betelgeuse
For previous data see Krisciunas and references therein The comparison star as
2
b efore was Ori V B V Transformation to the UBV system was
accomplished by means of observations of red blue pairs Hall
In Table and Figure we give the data p oints The nightly means are typically the
mean of three di erential measures Luedeke s data were taken with a cm re ector
situated at Albuquerque New Mexico and an Optec SSP photometer Krisciunas s
data of November Julian Dates and were obtained with the
Lowell m re ector at Cerro Tololo stopp ed down to a smaller ap erture and using a
dry ice co oled photometer standard V lter and a magnitude neutral density lter
His data of Julian Dates to were obtained with a cm re ector at the
m elevation of Mauna Kea Hawaii using the system describ ed by Krisciunas
Table Photometry of Betelgeuse Observers L Luedeke K Krisciunas The given internal errors
do not include the uncertainties attributable to the adopted extinction co e cients or the
transformation co e cient
Julian Date V Observer Julian Date V Observer
L L
L L
L L
K L
K L
L L
L L
L L
L L
L L
L L
L L
L L
L K
L L
L K
L K
L K
L
Figure V band photometry of Betelgeuse Triangles data of Luedeke Circles data of Krisciunas
Except for the Krisciunas data at the right hand side the internal errors of the individual p oints are on
the order of or smaller than the size of the p oints
Krisciunas also observed Ori as a check star in spite of the fact that it app ears to
b e slightly variable The mean of those measurements gives V for Ori
Bester et al have recently correlated this and previous photometry of Betel
geuse with mid infrared measurements of the diameter of the star Further photometric
monitoring is warranted
?
K KRISCIUNAS
??
K D LUEDEKE
?
Joint Astronomy Centre N A oh ok uPlace University Park Hilo Hawaii USA
e mail kevin jach hawaii edu
??
Giddings Avenue NE Albuquerque New Mexico USA
e mail compuserve com
References
Bester M Danchi W C Hale D Townes C H Degiacomi C G M ekarnia D and
Geballe T R Ap J
Hall D S I A P P P Communic No
Krisciunas K IBVS No
Krisciunas K Sky and Telescope No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
NSV AN RR LYRAE TYPE STAR IN OPHIUCHUS
NSV HV CSV GSC was announced as a variable
star by Hughes Boyce and Huruhata According to Kholop ov this ob ject
m m
is an RR Lyrae star with a photographic magnitude variation from : to : No
additional information is given
For days from May to June NSV was observed in the V
band using a Starlight Xpress CCD camera attached to the Newtonian fo cus of the m
telescop e at l Ametlla del Valles Observatory Spain GSC and GSC
were used as comparison and check stars resp ectively Figure
Observations showed that NSV is in fact an RR Lyrae star with an amplitude
m
of : in the V band an asymmetry factor M m P and a p erio d over hours
Figure Photometric measurements may b e slightly a ected by crowding due to the
fact that there is a faint star close to the variable which not always could b e satisfactorily
excluded in the synthetic ap erture reduction pro cess
Figure V NSV C Comparison star Ck Check star North is on top
Figure
The following ephemeris has b een also derived
d
Max HJD : E
Antonio GARRIGOS SANCHEZ
Grup d Estudis Astronomics
Apartado
Barcelona
Spain
e mail gea astro gea cesca es
References
Hughes Boyce E Huruhata M Annals of the Astronomical Observatory of the
Harvard College No
Kholop ov P N editor New Catalogue of Susp ected Variable Stars Moscow
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
GREAT OPTICAL OUTBURST OF A V TAURI
The recurrent transient X ray source A HDE identical to V Tau
optical variable was rst detected by the satellite Ariel V Rosenberg et al This
Be and neutron star binary system is actively observed in frequency range from X ray
to infrared see for example Giovannelli Graziati Gnedin et al Motch
et al Photometric b ehaviour of HDE was traced in detail in the pap er
by Lyutiy et al Hao et al investigated the semiregular secular variation
of brightness of the system by using Fourier analysis They noted also some evidence of
m
low amplitude less than : variation of the brightness on hours time scale Besides
observers mentioned sudden short time rises in brightness the so called blue ares with
m
large V : amplitudes R ossiger in December Gnedin et al
in April Maslennikov in April Berdnik et al in November
Figure The data of dual channel observations on Oct in Johnson s B lter a the
counts of A in channel comparison star counts obtained for the channel reduction are seen at
UT and hours b the count of the comparison star in channel reduced to the sensitivity
level of channel c V C data in relative magnitudes
Figure Observations in channel which demonstrate stability of the photometer s work a during
the outburst b after the outburst The sky background counts are seen b elow and the comparison
star s count ab ove The p oints are linked by a connecting line
Figure An enlarged part of Figure c b etween two of the brightest individual pulses
Our observations in the nights V lter Octob er B lter and
November B lter were the part of the Program Monitoring of Unique Astro
physical Ob jects of the Russian Ministry of Science The hours observational runs
were done with dual channel photometer attached to m Ritchey Chretien telescop e
at the Mt Dushak Erekdag observational station of Odessa Astronomical Observatory
Dorokhov et al The integration time was seconds HD m mag
A was used as a comparison star Then the data were reduced to sec integration
time
The great outburst was recorded in the night Oct JD from
UT to hours The date of the outburst is close to p eriastron passage of
the pulsar within the error limits if the orbital parameters by Margoni et al are
adopted T days P days But when we used more recent
orbital solution Finger et al derived from X ray observations such a coincidence
was not revealed
The data of two channel mo de are presented in Figure The observations started after
the outburst had b egun The outburst consists of a great number of transient individual
pulses The intensity at the burst s p eak was ab out ve times as large as that on the
m
b ottom level this night m :
In Figure the stability of the photometer s primary channel work is shown in two
parts of the observational run The detailed character of the outburst is b etter seen in
Figure which is an enlarged part of Figure Duration of one fast brightening amounts
to sec only which is comparable to the integration time The b ottom brightness
level b etween the pulses was stable during the outburst The observed undisturb ed
magnitude di erence variable comparison was mag in Oct the system
b ecame brighter by mag in Nov in lter B
N I DOROKHOV
T N DOROKHOVA
Astronomical Observatory
Odessa State University
Shevchenko Park
Odessa
Ukraine
References
Berdnik E V Gorshanov D L Maslennikov K L Somsikov V V Pis ma As
tron Zh
Dorokhov N I Dorokhova T N Komarov N S Mkrtichian D E Mukhamednazarov
S Astron and Astrophys Trans
Giovannelli F Graziati L S Space Sci Rev
Gnedin Yu N Zaitseva G V Larionov V M Lyutiy V M Khozov G V She er E K
Astron Zh
Hao J X Huang L Guo Z H A A
Finger M H Wilson R B Hagedon K S IAU Circ No
Lyutiy V M Za jtseva G V Latysheva I D Pis ma Astron Zh
Margoni K Ciatti F Mammano A Vittone A A A
Maslennikov K L Pis ma Astron Zh
Motch C Stella L Janot Pacheco E Mouchet M ApJ
Rosenberg F D Eiles C J Skinner G K Wilmore A P Nature
R ossiger S IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
July
HU ISSN
U B V LIGHT CURVES AND PERIOD BEHAVIOR FOR
THE SOLAR TYPE ECLIPSING BINARY V AQUILAE
As a part of our continuing study of short p erio d solar type binaries we have ob
h m s
tained well covered UBV light curves of V Aquilae :
GSC PPM BD V Aql was discovered by
Ho meister Soloviev classi ed it as a W UMa variable gave times of
d
minimum light and found it to have a p erio d of : One set of B V light curves formed
from normal p oints has b een published Faulkner A later pap er Faulkner
gave the following improved ephemeris
d
JD Hel Min I : E
Some ep o chs of minimum light are available in the literature including four photo
electric timings by Agerer and H ubscher six by Faulkner and many
visual photographic timings by BAV members see for instance K amper
Our present observations were obtained from July to at Lowell Observatory
in Flagsta Arizona A thermo electrically co oled EMI S S catho de PMT was
used in conjunction with the m Lowell re ector A nder chart is included as Figure
h m s
The variable is denoted as V while the comparison :
h m s
and check : stars are denoted as
C and K resp ectively Ab out observations were taken in each passband
Seven mean ep o chs of minimum light were determined from the observations made
during two primary and ve secondary eclipses using bisection of chords These minima
are given in Table accompanied by their probable errors in parentheses
Insp ection of the O C residuals of a full linear t to all the timings revealed two eras
of constant but di erent p erio ds connected by what may b e a smo oth transition see
d
Figure We calculated a p erio d of : for the rst era b efore JD
and the following improved ephemeris for the mo dern era
d
JD Hel Min I : E
s
The data indicates a p erio d change : statistically signi cant at the level
We nd that our identi cation of primary and secondary eclipses are reversed relative to
those in recent publications This is not surprising since the eclipse depths are nearly
equal
The linear ephemeris for late timings equation was used to calculate the O C
residuals in Table and the phases of the present observations More timings of minimum
light are needed b oth from photographic archives and future observations
Figure Finding chart mo di ed from a Digitized Sky Survey image of V Aql V
the comparison star C and the check star K
Figure O C residuals for all available times of minimum light as calculated from equation
Figure U light curve and U B color curve for V as magnitude di erences variable
minus comparison star
Figure B and V light curves and B V color curve for V Aql as magnitude di erences variable minus comparison star
Table Ep o chs of Minimum Light V Aquilae
JD Hel
Min Cycles O C Source
I AH
I PO
II PO
II PO
II PO
I PO
II PO
II PO
Sources AH Agerer and H ubscher PO present observations
The U B V light curves and U B B V color curves of V Aql as de ned by their
individual observations are shown in Figure and as di erential standard magnitude
variable comparison versus phase Our light curve solutions reveal that V Aql is a
W type W UMa binary with a mass ratio of and a ll out of A total eclipse of
min duration o ccurs in the primary minimum Reductions and analyses were largely
done by BP as a part of her spring and summer undergraduate research pro ject at Millikin
University RGS and BC acted as her advisors
?
RONALD G SAMEC
BRANDY PAULEY
?
Bob Jones University
BRIAN CARRIGAN JULIE FRENCH
?
Greenville SC USA
MI IN LOOI
Millikin University
Decatur IL USA
?
Visiting astronomer Lowell Observatory Flagsta Arizona USA
References
Agerer F and H ubscher J IBVS No
Faulkner D R IBVS No
Faulkner D R PASP
Ho meister C AN
K amper B C BAV Rundbrief
Soloviev A Tadjik Obs Circ
Soloviev A The Variable Stars
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
B V R I LIGHT CURVES OF THE SOUTHERN
C C
VERY SHORT PERIOD ECLIPSING BINARY V CENTAURI
The very short p erio d VSP eclipsing binary V Centauri S CoD
h m s
: galactic latitude : was discovered by
Ho meister while conducting a massive photographic survey of Sonneb erg plates
The variable was listed only as b eing short p erio d with an amplitude of magnitude
He later Ho meister published photographic light curves timings of minimum
light and the following orbital elements
d
JD Hel Min I : E
He classi ed the system as a W UMa contact binary with primary and secondary eclipse
m m
depths of : and : resp ectively After nearly thirty years of b eing observationally
neglected V Cen was added to a study of short p erio d eclipsing binaries Gomez et al
Gomez and Lapasset published an informative IBVS note which included
a partial photo electric V light curve timings of minimum light from six eclipses and
an up dated ephemeris
d
JD Hel Min I : E
They state that the system is a contact binary and that the di erence in eclipse depths
is magnitude In a rep ort on seven such systems Gomez and Lapasset com
plete B and V photo electric light curves as well as an improved ephemeris were published
d
JD Hel Min I : E
Gomez et al concluded their work on V Cen with a parameter search and
solution They found that the system had a T K inclination and a llout
No further work has b een published on this system V Centauri was observed as
part of a continuing e ort to obtain complete multiband photo electric light curves of short
p erio d solar type eclipsing binaries The present observations were made in May
at Cerro Tololo Inter American Observatory Chile The Yale m re ector was used in
conjunction with B V R I lters of the Johnson Cousins system and a dry ice co oled
C C
photomultiplier A mo di ed Digitized Sky Survey DSS image of the eld is shown as
h m s 0 00
Figure in which the variable comparison : :
h m s 0 00
and check : : : stars are designated V C and
K resp ectively Our comparison star provided the b est color match to the variable with
m
B V averaging : Check minus comparison star measurements indicate that the
comparison star s light output remained constant during the observing interval
Figure Finding chart mo di ed from a Digital Sky Survey image of V Centauri V the
Comparison star C and the Check star K
Figure O C residuals of V Centauri from Equation linear ephemeris
Two new precision ep o chs of minimum light were determined from observations made
during primary eclipses The bisection of chords technique Henden and Kaitchuck
was used to determine b oth minima Approximately timings of minimum light span
ning years were collected from the literature We have listed the new photo electric
ep o chs of minimum light in Table The new minima are rep orted as mean times from
the four passbands All available ep o chs of minima were introduced into a weighted least
squares calculation Photographic and visual minima were included with assigned weights
of allowing residuals to b e calculated From this we obtained the following improved
linear ephemeris
d
JD Hel Min : E
The residuals are given as O C in Table and shown in Figure A quadratic
ephemeris was also calculated using weights of and for photographic visual and
photo electric minima resp ectively and found to b e marginally signi cant
Figure B V R and I light curves of V Cen as de ned by the individual observations with
C C
preliminary solution overlaid
JD Hel Min E E
The residuals from Equation are given as O C in Table The high scatter in the
early timings and lack of go o d observational coverage precludes determination of long
term p erio d variability at this time New observations as well as recovery of plate minima
are keys to understanding the p erio d b ehavior of this system
Table
JD Hel Eclipse Type Cycles O C O C
I
I
The light curves reveal that V Cen is in a state of contact or near contact with
continuous changes in light in the out of eclipse p ortions of the light curve There is an
O Connell e ect with the maximum at phase Max I b eing higher than that at phase
The light curves of Gomez et al indicate the opp osite phase is higher
than phase Thus the region of enhanced activity has moved around the star Our
preliminary solution Wilson Wilson and Devinney shows the system
to b e in a state of shallow contact llout of with a rather high mass ratio M M
and an inclination The primary and secondary comp onent temp eratures are
K and K resp ectively with a phase shift of A graphical representation of
the preliminary solution t to our observations is given in Figure A thorough analysis
of the observations is in progress and will b e rep orted on elsewhere
We would like to thank Dr Kwan Yu Chen of the University of Florida for allowing
our continued use of the Catalog of Interacting Binaries Thanks also go to Mr Franz
Agerer for giving us the opp ortunity to access the BAV Database Lichtenknecker
in our search for complete p erio d histories We would like to acknowledge the Space
Telescope Science Institute and all its a liates for the use of DSS images in our work
Our gratitude go es to Mrs Brenda Corbin and Mr Gregory Shelton of the U S Naval
Observatory Library for all their help in literature histories
RONALD G SAMEC
JAMISON D GRAY
Department of Physics
STEPHANIE WOISSOL
Bob Jones University
Department of Physics
Greenville SC
and Astronomy
Millikin University
Decatur Illinois USA
This research was partially supp orted by funds from a Millikin University Summer
Undergraduate Research Fellowship
Visiting Astronomer Cerro Tololo Inter American Observatory National Optical
Astronomical Observatories which are op erated by the Asso ciation of Universities for
Research in Astronomy Inc under contract with the National Science Foundation
References
Gomez M and Lapasset E IBVS No
Gomez M Lapasset E Ahumada J Clara J J Minniti D Bol Asoc Arg
de Astr
Gomez M Lapasset E Ahumada J Farinas R Rev Mex Astron Astrof
Henden A A and Kaitchuck R H Astronomical Photometry Willman Bell
Inc Virginia
Ho meister C Astr Abh AN
Ho meister C Ver o Sonneberg
Lichtenknecker J AAVSO
Wilson R E ApJ
Wilson R E PASP
Wilson R E and Devinney E J ApJ
ERRATUM
In IBVS No issue Table contains incorrect data on the minima of V Cen The
revised table is as follows
JD Hel Eclipse Type Cycles O C O C
I
I
J D GRAY
S WOISSOL R G SAMEC
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
NINE NEW VARIABLES IN THE HERCULIS FIELD
This pap er continues the study b egun in my previous publication Antipin Nine
more new variables Var have b een discovered in the eld centered on
Her So the number of new variable stars in this eld has increased to mostly RR
type variables stars and eclipsing systems stars This study is based on Moscow
collection of photographic plates taken with the cm astrograph in Crimea
Tables contain information on the new variable stars The standard sequence near
M Arp and Johnson Forbes and Dawson was used to obtain magnitudes
of comparison stars given in Table Finding charts and phased light curves are shown
in Figures and resp ectively
This study was partially supp orted by the Russian Foundation for Basic Research
through grant No Thanks are due to Dr N N Samus for his attention
to this investigation and to S Yu Shugarov for help during photo electric observations
Figure Finding charts
Figure
Figure Figure
Remarks on individual stars
Var Blue on Palomar prints In minimum brightness the star is apparent on go o d
plates The duration of the b est observed outburst is b etween and days Figure
Outbursts JD
Var The star was observed photo electrically during three nights in July
JD Sixteen observations in B and V bands were obtained The obser
vations were made with a photo electric photometer at the cm re ector in Crimea
m m m m
The magnitude ranges are B V and average B V is
mag The primary minimum was not covered These observations are in go o d agreement
with photographic light elements The phased light curve Figure for Var includes
photo electric observations in B band
Var The minimum is shown in Figure Primary minima JD
Var Min I I
Table Co ordinates and Identi cations of Variable Stars
Var GSC
h m s
Var
Var
Var
Var
Var
Var
Var
Var
Var
Table Data on New Variable Stars
Var N JD Type Max Min M m Max Min Period
or D JD days
Var UG
Var EW
Var RRc
Var RRab
Var EA
Var RRab
Var RRab
Var EA
Var RRc
Table Comparison Stars
Var a b c d e f g h
Var
Var
Var
Var
Var
Var
Var
Var
Var
S V ANTIPIN
Sternberg Astronomical Institute
Universitetskij Prosp
Moscow Russia
References
Antipin S V Inf Bul l Var Stars No
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
Number
Konkoly Observatory
Budap est
August
HU ISSN
NEW SUPERNOVA ON MOSCOW PLATES
A new sup ernova was found in the course of the search for variable stars using the
p ositive negative metho d Moscow collection plates taken with the cm astrograph in
Crimea were used for this study The discovery was rep orted in IAU Circ No where
the sup ernova was designated as SN ab
The nding chart is given in Figure The parent galaxy is not included in the ma jor
catalogues of bright galaxies NGC IC UGC MCG but it has a Guide Star Catalogue
h m s 0 00
designation GSC non stellar ob ject J
Moreover co ordinates of the galaxy s center and of the sup ernova were measured on
our plates relative to GSC stars The co ordinates of the galaxy are in go o d agreement
h m s
with those in the GSC and the co ordinates of the sup ernova are
0 00
J So the distance from the center of the galaxy to the sup ernova is
00 00
W and N
The sup ernova was seen and estimated on plates The results are given in Table
A standard sequence near M Arp and Johnson Forbes and Dawson and a
CCD standard Field from Crampton et al were used to obtain the magnitudes
of the comparison stars Table The light curve is shown in Figure Op en circles are
uncertain observations The maximum was reached on JD September
and its brightness was B with an error of ab out mag
It is not p ossible to classify the sup ernova with certainty Our observations are only
near the maximum and the author cannot say anything ab out the light curve s shap e on
the descending branch and ab out the rate of the brightness decrease
Finally note that no ob ject on Palomar prints was seen at the sup ernova p osition The
author has lo oked through ab out plates that include the investigated region No sign
of this star was found except the announced case
The author is grateful to Dr N N Samus and N E Kuro chkin for their attention to
this investigation and to N N Pavlyuk for discussion of the results
Table Observations of the sup ernova
JD B JD B JD B
Figure
Figure
Table Comparison Stars
Star B
a
b
c
d
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
Crampton D Cowley A P Schmidtke P C Janson T and Durrell P AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
ECCENTRIC ECLIPSING BINARY STARS AS TEST OF GENERAL
RELATIVITY THE CASE OF V CYGNI
V Cyg BD V B V is a detached eclipsing
max
binary consisting of a pair of B V stars having an eccentric orbit e and an
orbital p erio d of P days Khaliullin was the rst to show that this
or b
binary could b e an imp ortant test case for General Relativity GR b ecause the apsidal
motion exp ected from GR is signi cantly larger than the classical apsidal motion arising
from the tidal and rotational distortions of the comp onent stars He found that the
rate of apsidal motion exp ected from GR is yr while the contribution to
GR
apsidal motion from classical e ects is yr Moreover the relativistic apsidal
cl
motion exp ected for V Cyg is large ab out times greater than the corresp onding
00
relativistic apsidal motion of Mercury Sun of yr
GR
From the data available at that time Khaliullin found go o d agreement b etween
the observed apsidal motion rate of V Cyg of yr yr and
obs
the theoretical combined relativistic and classical apsidal motion of yr
GR cl
However this determination of apsidal motion was based on only two ep o chs very accu
rate eclipse timings from his photo electric photometry made in and less accurate
photographic minima determinations of Karp owicz made during Since
several accurate times of primary and secondary minima have b een determined from
photo electric or CCD photometry Recently Wolf re determined the apsidal motion
using Khaliullin s data as well as more recent eclipse timings and derived a more re ned ap
sidal motion rate of yr yr However this revised apsidal motion
obs
rate is signi cantly smaller than exp ected from theory Using up dated values for the inter
nal structure constant see Claret and Gimenez theory predicts relativistic e ects
of yr yr and classical e ects of yr yr
GR cl
resulting in a combined apsidal motion rate of yr yr This re
GR cl
sult is particularly interesting b ecause in V Cyg most of the apsidal motion is exp ected
to arise from GR
Starting in the Spring of UBVR photo electric photometry of V Cyg has b een
conducted on the Villanova Fairborn m Automatic Photo electric Telescope APT at
Mt Hopkins Arizona During di erential photometry of the star was obtained on
photometric nights Nearly complete light curves have b een obtained and new eclipse
timings have b een made from these data The photo electric observations were carried out
using the usual observing sequence of sky comparison check variable comparison sky and
an integration time of seconds Because of the relative faintness of V Cyg blind
o sets from the p osition of the comparison star were used to acquire the star Initially
HD SAO m K I I I was used as the primary comparison star
v
and HD SAO m G I I I served as the check star However after
v
a few months into the observing program HD b egan to show evidence of small
systematic changes in brightness esp ecially in the U and B bandpasses
Figure A plot of the the V band light curve showing the secondary minimum in an
expanded phase scale
Figure A scale mo del of the system showing the orientation of the orbit and the stars
drawn to approximate scale
Figure A plot of the apsidal motion rate determination showing the change in the
displacement of the secondary eclipse D t t P with time
Fortunately frequent observations of the check star were made which enabled us to use
HD as the primary comparison star for the entire data set The observations
were reduced in the usual way in which times were converted to Helio centric Julian Day
Numbers and the magnitudes were corrected for di erential atmospheric extinction Be
cause of angular proximity of the variable comparison and check stars the di erential
extinction corrections were very small Nightly means were formed from the observations
outside of the eclipses typically observations comprise each normal p oint p er lter
The observations inside the eclipses were not averaged
Figure shows the V band light curve in which the phases were computed from the
light elements of Khaliullin the secondary minimum in an expanded phase scale
is also shown in the gure The eclipses are deep and very narrow secondary minimum is
well de ned and o ccurs near phase but primary minimum is p o orly covered and
needs further observations b efore it is satisfactorily de ned As shown by Khaliullin s
photometry the primary minimum is much broader than the secondary minimum b ecause
of the orientation of the orbit in which p eriastron and apastron o ccur near
to the times of the secondary and primary eclipses resp ectively A scale mo del of the
system showing the orientation of the orbit and the stars drawn to approximate scale is
shown in Figure
A very accurate determination of the time of secondary minimum was made from
UBVR photometry obtained near the lower p ortions of the minimum on the night of
July UT The time of mid eclipse was found from least squares ts of the data and
by the bisecting cord metho d Indep endent determinations of mid eclipse were made from
the di erent bandpasses No systematic di erences were found so that a mean timing was
calculated from the four data sets
d
T Min I I HJD
A new determination of apsidal motion was made using this timing along with tim
ings given by Khaliullin and Wolf In addition to these the photo electric
and CCD eclipse timings obtained by Lacy and Fox and Diethelm were
also included The photographic timings of Karp owicz were also included but
assigned lower weights than the photo electric or CCD observations The analysis of the
timings yielded an apsidal motion rate of yr yr This apsidal
obs
motion rate is very nearly the same as found by Wolf which was based on fewer
observations A plot of the apsidal motion rate determination is shown in Figure in
which the change in the displacement of the secondary eclipse with time is shown The
older photographic timing estimates were not used in the least squares determination of
the apsidal motion but the apsidal motion found from the mo dern data ts the older data
quite well More interestingly this study con rms that V Cyg has an observed rate
of apsidal motion that is signi cantly less than the theoretically exp ected apsidal motion
This smaller than exp ected apsidal motion found for V Cyg is di cult to explain and
the discrepancy is in the same sense as found for two other eclipsing binaries DI Her and
AS Cam in which the relativistic contributions to apsidal motion are also signi cant see
Guinan and Maloney Maloney et al Guinan et al
Sp ectroscopic observations of V Cyg have b een obtained several years ago by EFG
which indicate approximate stellar masses for the system of ab out M M M
and pro jected rotational velocities of the comp onents of v sin i v sin i
km s Ultraviolet sp ectrophotometry A has also b een obtained with the
IUE satellite and the preliminary analysis of this data indicates a mean temp erature
for the two stars of ab out T T K These temp eratures corresp ond to
sp ectral types of ab out B V A V These sp ectral types and temp eratures are in
go o d agreement with the B V and U B indices measured recently by Lacy after
the color indices are corrected for interstellar reddening
We plan to continue photometry of the star with the APT during to complete the
UBVR light curves in particular to cover fully the primary eclipse Also we are aware
that sp ectroscopic radial velocity observations of V Cyg are currently b eing conducted
at San Diego State University by Paul Etzel priv commun Once the light and radial
velocity curves are complete a more thorough study of this imp ortant binary can b e made
and a more de nitive determination of its orbital and physical prop erties can b e obtained
This study is supp orted by NSF grants AST and AST which we grate
fully acknowledge The reduction and analysis of the IUE observations were supp orted
by NASA Grant NAG
Edward F GUINAN
Jamison A MALEY
James J MARSHALL
Dept of Astronomy and Astrophysics
Villanova University
Villanova PA
U S A
References
Claret A and Gimenez A Astron Astrophys Suppl Ser
Diethelm R B B S A G Bul l
Guinan E F and Maloney F P Astron J
Guinan E F Marshall J J and Maloney F P I B V S No
Karp owicz M Acta Astr
Khaliullin Kh F Astr Circ USSR
Khaliullin Kh F Ap J
Lacy C H Astron J
Lacy C H S and Fox G W I B V S No
Maloney F P Guinan E F and Mukherjee J Astron J
Wolf M I B V S No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
NEW APSIDAL MOTION DETERMINATION OF THE ECCENTRIC
ECLIPSING BINARY V CYGNI
The eclipsing binary V Cyg HR HD BD V
max
B V consists of a pair of F V stars moving in an eccentric orbit e
and having an orbital p erio d of P days The system is detached with b oth
or b
comp onents residing well inside their resp ective Ro che lob es The orbital and stellar
prop erties of V Cyg are very well determined from the careful study of Andersen
et al One of the interesting asp ects of this binary that apparently has b een
overlooked is that its U V W space velocity comp onents as given by Andersen et al
of km s are very close those of the Hyades cluster
km s Eggen Eggen Note that the U V W velocity comp onents are
measured relative to the Sun and that the Eggen system is adopted in which a p ositive
U velocity is in the direction of the Galactic anti center Although the similarity b etween
the space motions of the binary and the Hyades Moving group could b e a coincidence it is
more likely that V Cyg is a member If this is true then the binary would b e co eval
with the Hyades thus having an age of ab out Myr Knowing the age of a binary
vastly increases its imp ortance for testing stellar structure opacity laws and evolution
mo dels e g Guinan
Because of V Cyg s eccentric orbit and deep narrow eclipses its apsidal motion
can b e accurately determined from an analysis of the timings of primary and secondary
eclipses The apsidal motion rate is determined from the change in the displacement of the
secondary eclipse relative to the primary eclipse e g Guinan and Maloney Inde
p endent determinations of the apsidal motion of V Cyg have b een made by Khaliullin
and Gimenez and Margrave they are in go o d agreement Khaliullin observ
ing an apsidal motion rate of yr yr while Gimenez and Mar
obs
grave observe yr yr However Andersen et al calculate
obs
a somewhat faster theoretical apsidal motion of yr yr in which the
exp ected relativistic and classical contributions to apsidal motion are yr
GR
and yr resp ectively The apsidal motion due to classical mechanics results
cl
from the comp onent stars departures from spherical symmetry which arises from the tidal
and rotational deformations of the stars The classical term dep ends on the fractional
stellar radii stellar masses rotation and orbital p erio d as well as on the distribution of
mass inside the stars The masses radii and rotation velocities of the comp onents are
well known The internal mass distribution of the stars is parameterized by the internal
structure constants k which are computed from stellar interior and evolution mo dels
e g Claret and Gimenez The relativistic apsidal term arises as a consequence of
General Relativity as in the case of Mercury s yr relativistic apsidal motion
Figure A plot of the primary eclipse of Octob er taken with the Str omgren
y lter
Figure A plot of the displacement of secondary minimum from the half p erio d p oint
vs ep o ch showing the observed apsidal motion rate
Photo electric photometry of V Cyg was conducted with the Jenkins cm re ector
at Villanova University Observatory The observations rep orted here were made on the
nights of and Octob er UT using intermediate bandpass blue A
max
and yellow A interference lters These were nights on which the secondary
max
and primary minima o ccur resp ectively The yellow lter has characteristics closely
matched to the Str omgren y lter Di erential photometry was carried out in the
m
usual manner using HD F m This star had b een used in previous
V
photometric studies of the system and app ears constant in light The observations were
corrected for di erential extinction and the times were converted to Helio centric Julian
Day Number HJD The photometry was reduced using a program developed by G P
McCo ok
For illustration the observations of the primary minimum is presented in Figure in
which the di erential magnitudes in the sense variable minus comparison star V C
are plotted against HJD for the yellow observations The mid times of the secondary and
primary eclipses were determined by least squares ts of the minima with parab olas and
also by bisecting cords see Guinan et al The two metho ds yield similar results
for the blue and yellow data sets of each eclipse The measured eclipse timings are
d
T Min I HJD
d
T Min I I HJD
These eclipse timings are very close to the times predicted using the light elements of
Gimenez and Margrave Thus indicating that the ephemerides given by them are
essentially correct
We added these timings to the photo electric eclipse timings already available see
Ko ch Khaliullin Gimenez and Margrave Guinan et al Caton and
Burns Lacy and Fox However the last two timings were only of primary
eclipse We then recomputed the rate of apsidal motion for the system This was done
following the pro cedure of Guinan and Maloney Indep endent linear least squares
solutions were made of the primary and secondary eclipses resp ectively yielding p erio ds
of P min I days and P min I I
days The p erio d determination from the primary eclipses is b etter determined than
secondary eclipses b ecause the primary eclipse has twice as many timings A plot of
the change of the displacement of secondary minimum from the half p erio d p oint D
t t P is shown in Figure This slow variation in the displacement of secondary
minimum is due to advance of the line of apsides of the orbit and the data yields an
apsidal motion rate of yr yr This value is nearly identical
obs
to those determined previously The reason for the relatively large error is explained
in two ways First there are only ve indep endent timings of secondary minima and
therefore the apsidal motion rate is still not well de ned Also in calculating the errors
we to ok the uncertainties in b oth of the p erio ds determined from the analysis of primary
and secondary eclipses and propagated them through the equations to calculate the total
uncertainty in the apsidal motion rate More timings in particular of secondary eclipses
are necessary to help de ne the apsidal motion rate more precisely so we plan to obtain
additional photometry of V Cyg In particular we hop e to obtain additional timings
of the secondary minimum
This work was supp orted in part by NSF Grant AST which we gratefully
acknowledge This research has made use of the SIMBAD data base op erated at CDS
Strasb ourg France
Joseph F BURNS
Edward F GUINAN
James J MARSHALL
Dept of Astronomy and Astrophysics
Villanova University
Villanova PA
USA
References
Andersen J Garcia J M Gimenez A Nordstr om B Astron Astrophys
Caton D B and Burns W C I B V S No
Claret A and Gimenez A Astron Astrophys Suppl Ser
Eggen O J M N R A S
Eggen O J Vistas of Astronomy
Gimenez A and Margrave T E Astron J
Guinan E F in New Frontiers of in Binary Star Research eds K C Leung and
I S Nha ASP Conf Ser p
Guinan E F and Maloney F P Astron J
Guinan E F Marshall J J and Maloney F P I B V S No
Guinan E F Na ja S I Zamani No or F Boyd P T and S M Carroll
I B V S No
Khaliullin Kh F Astron Tsirk No
Ko ch R H Astron J
Lacy C H and Fox G W I B V S No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
NSV IS AN OVERCONTACT ECLIPSING BINARY STAR
The variability of NSV BV CSV was announced by Geyer et al
who indicated that this star was a p ossible Cepheid with a photographic magnitude
m m
variation from : to : According to Kholop ov the sp ectral type of this
ob ject is A NSV can b e unambiguously identi ed with GSC a star
with a photovisual magnitude PAL V lter of
For nights from May to May NSV was observed in the V
band using the m telescop e at Mollet del Valles Observatory Spain and a Starlight
Xpress CCD camera As comparison star was used GSC with a photovisual
magnitude PAL V lter of
Observations show that NSV is not a Cepheid but an overcontact eclipsing binary
star with a p erio d over hours Phase curve shows that primary minimum is a transit
m
with a : depth and secondary minimum is an o ccultation with an average depth of
m
: It was also observed that Min I has a distorted shap e whereas shap e and depth of
Min I I changed from cycle to cycle during the observational p erio d
The following ephemeris was derived
d
Min I HJD : E
Light curve was preliminary solved using Binary Maker Bradstreet For
this purp ose the phase curve was reduced to normal p oints by dividing it into
non overlapping identical intervals and averaging individual observations within each
interval Average p oints were nally converted to ux In computing the photometric
solution the following parameters were initially adopted a mean surface temp erature
T K according to the sp ectral type of the system and gravity darkening co e cients
g g and b olometric alb edos A A which corresp ond to stars with radiative
external layers Limb darkening co e cients x and x were set to
Since there is no sp ectroscopic information ab out mass ratio a search for the solution
was carried out from q to q in mass ratio steps of b etween q and
q b etween q and q and b etween q and q Simple
insp ection showed that there were no adequate solutions out of the search interval As
b est t criterion minimum scatter of residual values obtained by subtracting the synthetic
ux curve from normals p oints was used Elements of the b est solution are given in Table
Figure shows sup erimp osed phase and synthetic curves
Solution of the light curve of NSV indicates that this ob ject is an A type W
UMa system with one of the smallest known mass ratios Additional sp ectroscopic and
photometric observations should b e carried out in order to more accurately determine the physical parameters of this binary star
Figure
Table
mass ratio
i
ll out
Omega Omega
a a
g s
b b
g s
c c
g s
d d
g s
g g
x x
A A
T K T K K
L L
Enrique GARCIA MELENDO
Josep M GOMEZ FORRELLAD
Esteve Duran Observatory
Grup d Estudis Astronomics
El Montanya Seva
Apartado
SEVA
Barcelona
Barcelona
Spain
Spain
e mail jmgomez astro gea cesca es
e mail duranobs astro gea cesca es
References
Bradstreet D H Binary Maker User Manual Contact Software Norristown
Pennsylvania
Geyer E Kipp enhahn R Strohmeier W KVB No
Kholop ov P N editor New Catalogue of Susp ected Variable Stars Moscow
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
THE NEW OVERCONTACT ECLIPSING BINARY STAR NSV
Following the program initiated by the Grup d Estudis Astronomics in in co
op eration with the Esteve Duran Observatory Foundation for observing p o orly studied
variable stars NSV was monitored in the V band for nights from March
to May using a CCD camera attached to the m telescop e at L Estelot Obser
vatory in L Ametlla de Mar Spain To p erform di erential photometry GSC
and GSC were chosen as comparison and check stars resp ectively
Geyer et al indicated that NSV BD CSV
BV was a p ossible RR Lyrae type variable with a photographic magnitude vari
m m
ation from : to : The star can b e unambiguously identi ed with GSC
an ob ject with a photovisual magnitude PAL V lter of
The present observations allowed to determine that NSV is not an RR Lyrae
but an overcontact eclipsing binary star with a p erio d over hours Primary minimum
m
is an o ccultation with a depth of : and secondary minimum is a transit with a depth
m
of : An O Connell e ect that amounts to m Max I Max I I was also
detected where Max I is at phase and Max I I at phase
The following ephemeris was also derived
d
Min I HJD : E
A preliminary mo del of NSV was computed using Binary Maker Bradstreet
applying the same analysis metho d describ ed by Gomez Forrellad and Garcia
Melendo after converting the phase curve to normal p oints The O Connell
e ect and light curve asymmetries that frequently app ear in overcontact binary systems
are currently interpreted as bright or dark areas on the binary comp onents In this case
an initial unsp otted solution was obtained and nally a sp otted mo del was recomputed
Initially the following parameters were xed to obtain the photometric solution a mean
surface temp erature T K according to the sp ectral type G given by Kholop ov
and gravity darkening co e cients g g and b olometric alb edos A A
which corresp ond to stars with convective external layers Limb darkening co e cients x
and x were set to Due to the lack of sp ectroscopic information ab out mass ratio a
search for the solution was carried out from q to q in mass ratio steps of
Once the unsp otted solution was reached it was re ned invoking a single sp ot No
further attempt was made to introduce more sp ots to improve light curve tting A co
latitude of was xed Sp ot radius colongitude and temp erature factor were adjusted
It was found that light curve was b est mo deled with a hot sp ot on the secondary comp o
nent Elements of the b est solution are given in Table Table lists sp ot parameters
Figure shows the light curve of NSV and Figure depicts the synthetic light
curve sup erimp osed on normal p oints
Figure Figure
Table
mass ratio
i : :
llout
Omega Omega
a a
g s
b b
g s
c c
g s
d d
g s
g g
x x
A A
T K T K K
L L
Table
Colatitude
Colongitude
Sp ot Radius
T
f
Enrique GARCIA MELENDO
Jaime NOMEN TORRES
Esteve Duran Observatory
Grup d Estudis Astronomics
El Montanya Seva
Apartado
SEVA
Barcelona
Barcelona
Spain
Spain
e mail jnomen astro gea cesca es
e mail duranobs astro gea cesca es
References
Bradstreet D H Binary Maker User Manual Contact Software Norristown
Pennsylvania
Geyer E Kipp enhahn R Strohmeier W KVB No
Gomez Forrellad J M Garcia Melendo E IBVS No
Kholop ov P N editor New Catalogue of Susp ected Variable Star Moscow
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
CCD PHOTOMETRY OF EIGHT SUSPECTED
CATACLYSMIC VARIABLES
Several CV candidates were selected from the Palomar Green Catalog Green et al
and the New Catalogue of Susp ected Variable Stars Kholop ov to con rm
or reject photometrically their prop osed CV nature and to search for orbital variability
and eclipses The observations were p erformed using the CCD camera on the Danish
m telescop e at the Europ ean Southern Observatory in Dec Jan Table
Di erential instrumental magnitudes were then derived relative to nearby comparison
stars on the same CCD image We present here results for eight targets which are unlikely
to b e CVs
PG
Sp ectrophotometry of this ob ject Zwitter and Munari revealed a hot continuum
with Balmer absorption lines An absorption line sp ectrum is often seen during an out
burst of a CV replacing the prominent emission lines at quiescence But PG
showed its usual brightness Photometric observations by Misselt and Shafter cov
ering more than three hours did not show obvious variability exceeding a mag level
Our photometry con rms their result PG is certainly a misidenti cation as a
CV
PG
This ob ject showed sp ectrophotometrically Zwitter and Munari the same b ehaviour
as PG Our photometric observations cover slightly more than two hours and
give no evidence for any variability scatter less than mag Also PG is
certainly not a CV
PG
This ob ject also proved to b e constant in brightness during the nearly three hour observ
ing run scatter less than mag and is very probably not a member of the CV class
NSV
Haro and Luyten suggested this blue star Var to b e a variable of the SS Cyg
type The photometry covering nearly three hours did not reveal variability ab ove a
mag level Therefore our observations do not supp ort the identi cation of NSV as
a CV
NSV
Ho meister classi ed this star S as a short p erio d variable A p ossible CV
nature is assigned in the NSV catalogue We observed this ob ject for nearly two hours
and found it to b e constant in brightness scatter less than mag NSV is very
probably a misclassi cation as a CV
NSV
The variability of this star was detected by Ho meister The ob ject is listed as a
p otential CV or RR Lyr star in the NSV catalogue Our photometry demonstrates that
it is an RR Lyr star NSV dimmed steadily by approx mag during the
hours observing run Figure
Figure Light curve of NSV obtained on Dec
NSV
Luyten et al regarded this blue ob ject LB as a U Gem star or p ossibly
nova Since no nding chart is available and no star could b e found at the given p osition
we prob ed several stars in the vicinity in fact nearly all stars in the sparse eld None
of them turned out to b e variable We conclude that either the co ordinates from the
literature are wrong or the magnitude of NSV is now b eyond the detection limit of
our frames approx mag
NSV V Car N Car
Perek detected this nova as an emission line ob ject on ob jective prism plates
Duerb eck traced its outburst history on Harvard plates and identi ed it on
the corresp onding ESO SERC chart with a mag star Our two observing runs for this
star three nights apart covering approx three hours each do not show any p erio dic or
non p erio dic variability The star was constant within mag and its relative bright
ness was the same for the two runs an unexp ected b ehaviour for a p ostnova Assuming the
identi cation as b eing correct we had a closer lo ok at a three dimensional representation
00
of the brightness pro le of the star and found two bumps in the wings one ab out :
00
towards NE and one ab out towards NW Application of PSF techniques isolated two
stars of approx and mag resp ectively One of these is presumed to b e the p ostnova
From the scatter of the combined brightness of the three stars we place an upp er limit on
the variability of the two fainter ones at an approx and mag level resp ectively
Table Journal of observations Start is the time for the midp oint of the rst exp osure Duration
includes also gaps due to any interruption of the exp osure series Magnitudes photographic are from
the literature Observations were p erformed in integral light except for NSV where a Johnson B
lter was used
Ob ject Date Start Duration Int Time Frames Mag
UT h s No
PG Dec
PG Dec
PG Dec
NSV Dec
NSV Dec
NSV Dec
NSV Jan
NSV Dec
Dec
R HAEFNER
A FIEDLER
S RAU
Universit ats Sternwarte
Scheinerstr
M unchen
Germany
References
Duerb eck H W IBVS No
Duerb eck H W Sp Sc Rev
Green R F Schmidt M Lieb ert J ApJS
Haro G Luyten W J TTB No
Ho meister C Astr Abh No
Kholop ov P N New Catalogue of Susp ected Variable Stars Nauka Moscow
Luyten W J Anderson J H Sandage A R SFBS Univ of Minnesota
Minneap olis
Misselt K A Shafter A W AJ
Perek L BAC
Zwitter T Munari U A AS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
August
HU ISSN
NEW OBSERVATIONS OF FOUR GALACTIC CEPHEIDS
We have obtained CCD observations of a number of Cepheid variables which have b een
mostly ignored probably b ecause they are unreachable with mo derate size telescop es and
photo electric equipment We have employed bit CCD systems to obtain results for
several Cepheids which did not have photo electric light curves or had not b een observed
during the past years or so
We have chosen a series of comparison stars for di erential observations and we include
here simple statistics on their variability Finder charts for the fainter Cepheids are some
times di cult to obtain and we have included CCD nder charts of these Cepheids and
comparison stars Our nder charts should facilitate identi cation for future observations
of these stars
CCD observations were obtained with the Virginia Military Institute s m DFM tele
scop e with a bit Photometrics CCD system and the U S Air Force Academy s m
DFM telescop e also with a bit Photometrics CCD system V and R lters were chosen
to match the Johnson standard system with the CCD sp ectral resp onse Bessell
We obtained CCD images of a standard eld in M Schild and have obtained sat
isfactory transformations to the Johnson system Our observations have b een transformed
to the Johnson V and R system We had problems with some of the early V observations
b ecause of a bad lter therefore we have more R observations than V observations
Figure CCD nder chart for CY Aur V Cas HZ Per and SX Per North is at top
east is at left The image size is approximately on each side
All CCD images have b een at elded and all but a couple of images have had bias
and dark counts subtracted b efore at elding no dark counts were discernible on the
USAFA images Exp osures were standardized at four minutes for the VMI images and
six minutes for the USAFA images Magnitudes were obtained at VMI with DAOPHOT
and at USAFA by summing counts inside a square ap erture
CCD nder charts for each of the Cepheids discussed b elow are shown in Figure For
some of these stars we were unable to unambiguously identify the variable until we had
a few images centered on the variable s co ordinates even using the Hubble Guide Star
Catalog and GCVS p ositions The R bandpass light curves are shown in Figures
The eld of view of these nder charts VMI images is approximately arcminutes the
original scale is mm We found it di cult to compare our elds with some of the
original nder charts from or years ago since those nder elds generally hand
drawn or traced often covered up to one degree and fainter stars were not shown The
e ective bandpass was also generally di erent
All stars on our images which were reasonably non variable and bright enough for go o d
statistics were used to form an average for each eld to stars which was then used
to obtain a di erential magnitude with the variable star
Our light curves have b een graphed at an arbitrary ep o ch to place maximum light at
phase The ephemeris used to calculate this phase is shown in the caption of each
graph where the zero ep o ch corresp onds to the new normal maximum to aid in checking
long term p erio d changes or for comparison of p eak light with other data The p erio ds
used to calculate the phase in these graphs were obtained from the GCVS
CY Aur The nder chart app ears to agree with that given in the GCVS We could
not nd any photo electric photometry of this Cepheid as we b egan this pro ject although
we have now found observations from Berdnikov and Schmidt et al A
photographic light curve and the original nder chart are given in Kuro chkin
We graphed our R di erential magnitudes in addition to R magnitudes from Berdnikov
these data were obtained from the Welch Cepheid database see Figure We shifted our
di erential measures arbitrarily in magnitude to corresp ond with his Johnson values
We found go o d agreement with his data although some sections of the phase diagram
are still inadequately covered
V Cas This Cepheid shows an exceptionally well behaved light curve esp ecially
in the R band Although our light curve is p o orly covered just b efore p eak light the
rest of the curve is well de ned The comparison stars are also very stable Our nder
chart agrees with the original chart We have also graphed the R data from Berdnikov
data from Welch database our di erential data have b een shifted by an arbitrary
amount to coincide with Berdnikov s data See Figure
HZ Per We lo cated the original nder chart for HZ Per and there were no problems
in identifying this star We also graphed Berdnikov s data for comparison The
light curve is shown in Figure and although the comparison stars we used are well
00
b ehaved with a standard deviation of : in V the light curve of the Cepheid is noisy
particularly on rising light on the red image
SX Per We have some misgivings ab out agreement with the original nder chart on
this star although there seems to b e no doubt ab out having the correct star since the
p erio d agrees The light curve is shown in Figure A light curve and nder chart are
given by Kuro chkin Henden also published photo electric data for SX Per
Figure Light curve for V Cas R Figure Light curve for CY Aur R
bandpass See Figure for details bandpass Initial ep o ch is
d
and GCVS p erio d is : Julian day and the GCVS p erio d is
d
: Squares are our data plus marks
denote Berdnikov s observations
Figure Light curve for HZ Per R band Figure Light curve for SX Per R band
pass See Figure for details pass and GCVS p erio d
d d
and GCVS p erio d is : is :
Table Standard Deviations of Comparison Star Di erences
CY Aur V Cas HZ Per SX Per
Stars Stars Stars Stars
m m m m
: : : :
We have included a summary of our results with the comparison stars in our CCD
elds In Table is a listing of the standard deviations of our magnitude di erences of
comparison stars which we used to obtain di erential magnitudes R bandpass We used
the comparison stars shown in Table to derive an average magnitude which was then
subtracted from the magnitude of the Cepheid The V and R data have b een dep osited
in the Welch Cepheid database http www physics mcmaster ca Cepheid
We wish to acknowledge the supp ort of our two institutions in encouraging this re
search D L D acknowledges a sabbatical award and several V M I Summer Research
Grants in supp ort of this work R H B acknowledges generous telescop e time from the
U S Air Force Academy We also wish to acknowledge a National Science Foundation Re
search in Undergraduate Institutions grant AST which was used to purchase
computer equipment for DAOPHOT data reduction with matching funds from V M I
This research has made use of the SIMBAD database op erated at CDS Strasb ourg
France
Raymond H BLOOMER Jr
David L DUPUY
Department of Physics
Department of Physics and Astronomy
King College
Virginia Military Institute
Bristol TN
Lexington VA
rhbloome king king bristol tn us
dupuy vmi edu
References
Berdnikov L N Variable Stars
Berdnikov L N Astron and Astrophys Transactions
Berdnikov L N Pis ma Astron J
Bessell M S PASP
Henden A A MNRAS
Kuro chkin N E Sov Var Stars No
Schild R PASP
Schmidt E G Chab J R and Reiswig D E AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
CH CYGNI A TENTH MAGNITUDE STAR
CH Cygni is a p eculiar binary system in which a magnetic white dwarf accretes matter
from the M giant s wind moving on a long p erio d highly eccentric orbit Miko lajewski
et al and references therein It is known as the brightest symbiotic star During
m
its V brightness was ab out and the star was seen even by the naked
m
eye Recently its brightness dropp ed signi cantly and reached almost in visual
the dimmest value ever observed Several p erio ds of high activity separated by quiet ones
have b een observed since During the outbursts a hot F A continuum and numerous
emission lines dominated in the UV and optical The late M giant in the system dominates
the sp ectrum b etween active phases and shows di erent kinds of variability
Photo electric UBVRI and UBV observations were continued using the cm and cm
telescop es at Toru n and Tartu observatories resp ectively see Leedj arv Miko lajewski
Miko lajewski et al The UBVRI light curves covering the last decade are
shown in Figure After the eclipse Miko lajewski et al the star reached a
d
quiet inactive state by the end of during which a pure M giant s pulsations with
m
an amplitude of started to dominate the BV bands During the star showed
some transitory months episo des of activity clearly visible in U light Starting from
the early a relatively strong and long activity p erio d has b een developing with two
gaps in the ends of and An additional F type sup ergiant continuum from the
hot comp onent Kuczawska et al has mo di ed the light curves in all wavelengths
Kuczawska et al have also demonstrated evidence of a ickering down to the RI bands
in July
d
In the mid the hot continuum dropp ed rapidly During the last three four
pulsations of the M giant which are of a similar shap e and amplitude as were previously
observed b etween and Miko lajewski et al those pulsations b ecame the
main features in the BV light curves
Another pronounced variability of the M giant is probably connected with o ccupation
of the star s surface by large co ol sp ot or sp ots and the rotation of the star with a p erio d
of ab out days Miko lajewski et al We have found all observed broad minima
of this p erio dicity using all available photo electric data Miko lajewski et al
and references therein In BV lters minima were observed during inactive phases only
Only two out of minima Table are not compatible with this p erio dicity At least the
last one JD is probably caused by drop of earlier observed F type continuum of
the active comp onent From the other minima in Table we have obtained the following
ephemeris
JD Min E
d
The O C values for this ephemeris are also listed in Table The p erio d is
practically the same as the value of days found by Hinkle et al which they
interpreted as an orbital p erio d of an inner symbiotic pair on eccentric orbit in their
triple star mo del of CH Cygni
d
Table Observed minima of the p erio dicity
E Min Filters O C E Min Filters O C
JD days JD days
BV VRI
BV BVRI
BV BVRI
BV RI
BV RI
BVI RI
Figure The UBVRI light curves of CH Cygni including the last minimum in June
In the lowest b ox the calculated minima from ephemeris are marked
Apart from an increasing p erio d of pulsation Miko lajewski et al have
found another evidence of a luminosity pulse pro duced by a helium ash on the AGB for
the M giant in CH Cyg a systematic decrease in the optical light on the time scale
m
of hundred years The rate was estimated to b e ab out yr in the visual from
m
historical data and seems to achieve at least yr during the last decade
In conclusion the minimum of brightness observed in June is a result of
inactivity of the hot comp onent secular decline of the M giant s brightness and
d d
coincidence of the minima of p erio dicity rotation and pulsation In Figure
we show V magnitudes together with U B and B V indices during last two years We
have marked two last minima with ep o ch E and E calculated from Eq and
last four from e to e minima predicted by the quadratic ephemeris
JD Min e e
for the M giant s pulsations Miko lajewski et al The last three pulsation minima
are evidently visible in the V light Observed minima con rm the systematic increase of
d
the pulsation p erio d which reaches now almost Taking into account the secular
decrease of brightness in the optical we can predict from Eqs and the next
coincidence of minima in July when an even deep er minimum should b e observed
if the hot comp onent remains inactive
Figure The OI I I A and A Figure The V light curve and U B
region in the sp ectrum of CH Cygni and B V indices of CH Cyg during last
years Last ep o chs of minima from
ephemerides and are marked as E
and e resp ectively
Sp ectral observations during the last three years were carried out with a CCD camera
mounted in the coud e spectrograph of the m telescop e at NAO Rozhen In Figure
the b ehaviour of the nebular lines of OI I I A and A as well as the changes
in the hot veiling continuum during the drop of star s brightness in May June are
shown It is obvious that the ux in the continuum decreases during all the time and that
the OI I I nebular lines reached a maximum intensity coinciding with the light minimum
00
in June At the same time a nebula extended to ab out was observed in the
optical by Corradi Schwarz Variations in the intensity pro le shap es and strong
dep endence on the slit orientation for the nebular lines of OI I I were observed in
Tomov et al So it is evident that there is a signi cant amount of relatively low
density matter around the CH Cyg system which may b e resp onsible for the origin of
the nebular lines
Acknowledgement This research was sp onsored by the Polish KBN Grant No P
Bulgarian NFSR Grant No F and the Estonian Science Foundation
Grant No
M MIKO LAJEWSKI
Institute of Astronomy
Nicolaus Cop ernicus University
Chopina Toru n
Poland
e mail mamiko astro uni torun pl
T V TOMOV D KOLEV
NAO Rozhen
P O Box
Smolyan Bulgaria
e mail rozhen tempus tu plovdiv bg
L LEEDJARV
Tartu Astrophysical Observatory
EE T oravere Estonia
e mail leed aai ee
References
Corradi R Schwarz H Physical Processes in Symbiotic Binaries and Related
Systems ed J Miko lajewska Foundation for Polish Astronomy Warsaw in press
Hinkle K H Fekel F C Johnson D S Scharlach W W G AJ
Kuczawska E Miko lajewski M Kirejczyk K IBVS No
Leedj arv L Miko lajewski M A A
Miko lajewski M Tomov T Miko lajewska J Ap SS
Miko lajewski M Miko lajewska J Khudyakova T N A A
Miko lajewski M Miko lajewska J Khudyakova T N A A
Miko lajewski M Miko lajewska J Tomov T Compact Stars In Binaries eds J
van Paradijs et al Kluwer Dordrecht p
Tomov T Kolev D Munari U Antov A MNRAS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
THE SUPEROUTBURST OF RZ SAGITTAE
RZ Sge has b een known as an SU UMa type dwarf nova since the discovery of sup erhumps
during the sup eroutburst Bond et al Since no further photometric study
of this ob ject has b een published so far we underto ok time resolved CCD photometry
during the August sup eroutburst in order to re ne our knowledge on this ob ject
Observations were carried out using a CCD camera Thomson 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 dead time an on
chip summation of 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 dep ending on the brightness of the ob ject the read out and data saving time
was typically s A total of useful ob ject frames were obtained on nights b etween
August and
Table Journal of observations of RZ Sge
Date Start End Exp osure Frames
h m h m s
August
These frames were after corrections for standard de biasing and at elding pro cessed
by a micro computer based ap erture photometry package developed by the author The
di erential magnitudes of the variables were determined using the lo cal standard star C
in Figure whose magnitude was given as V by Misselt A comparison of
the lo cal standard star with a check star C in Figure in the same eld has con rmed
the constancy of the standard during a run and gives the exp ected standard error in the
di erential magnitudes for the variable as mag for a single frame on ideal nights
Helio centric corrections to the observed times were applied b efore the following analysis
The overall light curve constructed from our observations is shown in Figure The
1
light curves shows a slow linear decline with a rate of mag day characteristic to a
sup eroutburst of an SU UMa type dwarf nova followed by a rapid decline on August
Detailed light curves on individual nights are shown in Figure clearly demonstrating the
existence of sup erhumps with amplitudes of mag and recurring every
day The amplitude of sup erhumps seem to have attained a maximum on August four
days b efore the termination of the sup eroutburst Such a late growth of sup erhumps may
b e related to a similar phenomenon observed in a large amplitude SU UMa type dwarf
nova V Cyg Baba et al in preparation
0
N
50
100
C2 C1
pixel 150 E RZ
200
250
0 50 100 150
pixel
Figure Finding chart of RZ Sge drawn from a CCD image North is up and the eld
of view is ab out arcmin The comparison stars C C and RZ Sge RZ are marked
0 RZ Sge (1994 August)
.5
1 Relative V Magnitude 1.5
2
6 7 8 9 10 11 12 13
HJD - 2449570
Figure Overall V band light curve of RZ Sge during the August sup eroutburst
The zero corresp onds to V
0 RZ Sge Aug. 11
.5
1 Aug. 12
1.5 Aug. 13 Relative V Magnitude 2 Aug. 14
2.5 Aug. 15
3
-.05 0 .05 .1 .15 .2
Fraction of HJD
Figure Detailed V band light curves of RZ Sge Each light curve is o set by mag
After removing a linear trend of decline a p erio d analysis was applied to observations
using the Phase Disp ersion Minimization PDM metho d Stellingwerf for the Au
gust data The resultant theta diagram is shown in Figure The lowest minimum
1
at a frequency of day corresp onds to a p erio d of day
min giving a slightly longer p erio d than published by Bond et al This value
is slightly di erent from that determined by the maxima times of sup erhumps cf Table
caption This is b ecause the PDM uses data p oints distributed in all phases whereas
maxima times rely only on p oints around maxima The p erio ds determined using these
two metho ds may b e systematically di erent when the pro le of semi p erio dic signals
varies as is usual for sup erhumps We have adopted the PDM value since this metho d
usually gives b etter statistics than the other
Table Observed sup erhump maxima of RZ Sge O C and O C are calculated by equations of
1 2
6 2
M ax HJD E and M ax HJD E E
resp ectively
HJD E O C O C
1 2
1.1 RZ Sge
1
.9
.8 Theta
.7
.6
.5
10 12 14 16 18 20
Frequency
Figure Theta diagram Stellingwerf of p erio d analysis
By applying least squares tting to ve well observed maxima times of sup erhumps we
obtained the following ephemeris of maxima times
6 2
M ax HJD E E
5
which corresp onds to P of This value is within the usual range of p erio d
changes of sup erhumps in SU UMa type dwarf novae Patterson et al
Part of this work is supp orted by a Research Fellowship of the Japan So ciety for the
Promotion of Science for Young Scientists Requests for the observational data should b e
directed to T Kato tkato kusastro kyoto u ac jp
Taichi KATO
Dept Astron Faculty of Sci
Kyoto University
Sakyo ku Kyoto Japan
References
Bond H E Kemp er E Mattei J A ApJ L
Misselt K A PASP
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
Patterson J Bond H E Grauer A D Shafter A W Mattei J A PASP
Stellingwerf R F ApJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
PHOTOMETRY AND ASTROMETRY OF VARIABLE STARS
The Carlsb erg Automatic Meridian Circle on the Canary Island of La Palma makes
thousands of measurements of star p ositions and V magnitudes each year and the results
have b een published in a series of catalogues CMC CMC CMC
CMC CMC Amongst these stars are several thousand variable stars A
sp eci c programme of measuring the p ositions of variable stars with maxima in the range
V to was started in This range was chosen to include stars which are to o
faint to b e observed by the HIPPARCOS satellite
This note is to draw the attention of those interested in b oth astrometry and photom
etry of variable stars that the compilation of these results will b e available so on from the
CAMC group and also to p oint out that a substantial archive of variable star photometry
is already available in the Carlsb erg Meridian Catalogues
Photometry is carried out through a Johnson V lter see Helmer and Morrison
for full details of the passband Nightly calibration is made using ab out photo electric
standards A colour equation is derived for each annual catalogue allowing corrections
to b e made if the sp ectral type of the star is known If no sp ectral type is available the
m
star is assumed to have a B V colour index of : Mean errors range from ab out
m
magnitude for a single observation at the zenith of stars of V or brighter to
m
ab out : for a star near the limiting magnitude of V The results presented in an
App endix in each Carlsb erg Meridian Catalogue give the observed V magnitude on each
photometric night for all stars known to b e variable
Positions are made by reducing observations di erentially with resp ect to a grid of FK
stars The accuracy of the p osition also dep ends on the brightness the zenith distance
m
and the number of observations made A typical value for a star of V observed
00 00
at the zenith on nights is : in RA and : in Dec The CAMC can observe stars
from to declination Prop er motions are also listed in the catalogues when
rst ep o ch p ositions are available usually from the Astrographic Catalogue The data
taken by the CAMC b etween and is b eing prepared for inclusion on a CD ROM
which will b e available in the near future It will contain entries on stars of which
are recognised variables The total number of photometric observations of these
stars is An additional observations of recent novae and sup ernovae are also
included In the meantime the CAMC group b elow will b e glad to deal with any enquiries
for data from individuals
For further information contact the author at the address b elow or by E mail to
merlp ast cam ac uk
The CAMC pro ject also has a WWW page at
http www ast cam ac uk dwe SRF camc html
R W ARGYLE
Royal Greenwich Observatory
Madingley Road
Cambridge CB EZ
United Kingdom
References
Carlsb erg Meridian Catalogue No Observations of p ositions of stars and planets May
to Feb CMC Cop enhagen University Observatory Royal
Greenwich Observatory and the Real Instituto y Observatorio de la Armada en
San Francisco
Carlsb erg Meridian Catalogue No Observations of p ositions of stars and planets May
to Dec CMC Cop enhagen University Observatory Royal Green
wich Observatory and the Real Instituto y Observatorio de la Armada en San Fran
cisco
Carlsb erg Meridian Catalogue No Observations of p ositions of stars and planets Jan
to Dec CMC Cop enhagen University Observatory Royal
Greenwich Observatory and the Real Instituto y Observatorio de la Armada en San
Francisco
Carlsb erg Meridian Catalogue No Observations of p ositions of stars and planets Jan
to Aug CMC Cop enhagen University Observatory Royal
Greenwich Observatory and the Real Instituto y Observatorio de la Armada en San
Francisco
Carlsb erg Meridian Catalogue No Observations of p ositions of stars and planets Aug
to Dec CMC Cop enhagen University Observatory Royal
Greenwich Observatory and the Real Instituto y Observatorio de la Armada en San
Francisco
Helmer L and Morrison L V Vistas in Astronomy Part
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
BVRI PHOTOMETRY OF CG CYGNI
CG Cygni in the catalog of Strassmeier et al is a member of the short
p erio d eclipsing RS CVn class of stars Zeilik et al mo del the sp ot structure for
available data from to and review the literature on this star Heckert
mo dels BVRI data Continuing with this work I observed CG Cyg on the nights of
and August with the San Diego State University cm telescop e on
Mt Laguna The instrument and pro cedure were the same as describ ed in Heckert
The data plotted in Figures and are di erential magnitudes variable comparison in
the standard Johnson Cousins system The data les may b e obtained from the author I
mo deled the data using the Information Limit Optimization Technique ILOT describ 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 latitude and radius of a K
circular sp ot Figures and show these ts for the V band Performing the ts for each
wavelength indep endently I get the sp ot ts summarized in Table
Table Sp ot ts
B band V band R band I band
Longitude
Latitude
Radius
2
Table Clean ts
B band V band R band I band
U
L
1
k r r
2 1
r
1
i deg
L
2
q M M
2 1
2
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 ALBs at
and These mo dels show the same phenomenon Compare the sp ots to those
in Heckert nds two sp ots in The sp ot that was in the ALB during
Figure CG Cyg B and V light curves
Figure CG Cyg R and I light curves
Figure CG Cyg V band initial and clean ts
Figure CG Cyg V band sp ot t
disapp eared At the same time the sp ot in the ALB roughly doubled in radius
from to at V It however remained to within errors at the same longitude and
latitude 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 the clean ts summarized in
Table
For easy comparison Table shows the average values of the clean ts for the color
indep endent parameters from this work Heckert and Zeilik et al The
errors quoted are the standard deviations of the values averaged rather than the errors
returned from the ILOT program Most previous values of the mass ratio are Naftilan
and Milone Sowell et al Jassur gets and Popper gets
Zeilik et al adopted and did not t for the mass ratio This work and
Heckert lend credence to the lower value of the mass ratio found by Popper
Table Means for Clean Fits
k r r r i deg q M M
2 1 1 2 1
This Work
Heckert
Zeilik et al xed
The ILOT program also makes a b est t correction to the phase of primary minimum
From this information averaged over wavelengths I nd that the eclipses are observed
days after 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 American Astronomical So ciety Small Grants Program and Western Carolina
University for nancial supp ort
P A HECKERT
Dept of Chem Physics
Western Carolina University
Cullowhee NC
USA
References
Budding E and Zeilik M Astrophys J
Heckert P A Inf Bul l Var Stars No
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 Bud
ding E and Banks T S Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
HD A NEW SEMIREGULAR VARIABLE
We rep ort the discovery of the variability of the star HD The ob ject has b een
observed as a comparison star for the semiregular variable TU CVn but turned out to
b e variable
m
Although HD is a rather bright ob ject m : its variability was unknown
V
Schild found a sp ectral type of M I I I while the SAO catalogue gives M The
General Catalogue of Radial Velocities lists a radial velocity of km s The star has
m
b een observed by IRAS Its colour index of : indicates that this ob ject has
no circumstellar dust
The observations were obtained by using the Pho enix Rob otic Telescope at Mt Hop
kins in spring The telescop e observes in the Johnson UBV system using a diaphragm
00
of in diameter The internal standard error of the data lies b elow mmag As check
m
star for our comparison star we used HD a K giant with m : V
-3000
-2750
-2500 U
-2250 B -2000 (mmag) m
∆ -1750
-1500 V
-1250
2450150 2450200 2450250
JD
Figure Observed light changes of HD relative to HD in Johnson U B
and V
Without having a second nonvariable star for comparison we can only susp ect that
HD is the variable ob ject The six published values for the V brightness of the K
m
and in addition Eggen found that most of the M type giant di er by less than :
giants are variable Thus the variability of HD seems to b e very likely Due to the
absence of an observer at the telescop e we had to check the p ossibility of a misidenti ca tion
1.0
0.8
0.6
0.4 Amplitude
0.2
0.0 -0.02 0 0.02 70
60
50
40
30
20 -Amplitude (mmag) V 10
0 0 0.02 0.04 0.06
Frequency (c/d)
Figure Results of the Fourier analysis of the observational data The upp er plot
shows the sp ectral window the lower plot the amplitude sp ectrum
-2000
-1800 B -1600 (mmag) V m
∆ -1400
-1200
0 0.5 1 1.5 2
Phase (P =28.5d )
Figure Phase diagram for HD based on a p erio d of days For a b etter
illustration of the variation the data p oints have b een rep eated for a second cycle
In uence by a nearby ob ject or a wrong p ointing of the telescop e can b e excluded No
nearby ob ject is bright enough to disturb the measurement The measured B V value of
m
ab out : for the variable is typical for early M type stars and is very close to the data
found in the literature Schild But there is no M type star within degree except
the original program star TU CVn Therefore we are convinced that the correct star
has b een observed
Figure shows the variations measured relative to HD in U B and V The star
m
varies cyclically with a full amplitude of ab out : Two light cycles are well de ned
a third one is sampled more sparsely The light curve shows a strong asymmetry which
seems to change after JD The B V color index is changing irregularly only up
m
to ab out : and these variations are within the observational errors
In order to derive a p erio d for the light variations we did a Fourier analysis of the data
The results for the V measurements are plotted in Figure From this analysis we found
a p erio d of ab out days The B data lead to a very similar result With this p erio d
we plotted a phase diagram for the B and V measurements Figure
We think that HD is a semiregular variable of type SRb due to its small am
plitude although its light changes seem to b e rather regular Using the classi cation for
SRVs de ned by Kerschbaum and Hron we classify this star as blue SRV This
classi cation is based on the amplitude the p erio d and the IRAS color All these
values found for HD are typical for blue SRVs
The fact that the variability of such a bright star has not b een discovered earlier is
very interesting for the investigation of semiregular variables b ecause it indicates that
even samples of bright SRVs are not complete
Acknowledgements
This investigation has b een supp orted by the Fonds zur F orderung der wissenschaftlichen
Forschung under pro ject number S AST We wish to thank Mike Seeds for adding
our stars to the list of program stars for the Pho enix telescop e This research has made
use of the SIMBAD database op erated at CDS Strasb ourg France
T LEBZELTER
F KERSCHBAUM
Institut f ur Astronomie
Universit atWien
T urkenschanzstr
A Wien
Austria
LEBZELTER astro ast univie ac at
References
Eggen O J AJ
Kerschbaum F Hron J A A
Schild R E AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
LONG TERM BEHAVIOR OF THE
ECLIPSING BINARY PX CEPHEI
PX Cep is an eclipsing binary whose variability was discovered by Romano a
b and was given the preliminary name GR Kholop ov According to the
m m
GCVS its photographic magnitude varies b etween : and : The p osition of the
h m s
variable is given as B but at this lo cation no star brighter
m
than can b e found neither on the Sonneb erg astrograph plates nor in the POSS
database see Figure
Figure POSS section containing PX Cep upp er b ox and its p osition as given in
0 0
GCVS lower b ox The size of the eld is approximately North at the top
East to the left
Using the discoverer s nding chart PX Cep was found at the co ordinates
h m s
: B
h m s
or : J resp ectively
and is identical with GSC
1 http arch http hq eso org cgi bin dss
In Table we summarize the elements for PX Cep as given in the literature
Table Elements for PX Cep
ep o ch HJD p erio d d mag reference
unknown pg GCVS
V Boninsegna
Borovi cka
Borovi cka collected all minima given in the literature There is a large gap
b etween and for which time interval no observations have b een published so
far Borovi cka found an O C that suggested a changing p erio d
In an attempt to ll the gap in the data PX Cep was measured on ab out pho
tographic plates from the Sonneb erg plate collection taken b etween and For
the determination of the target s minima Argelander s metho d was applied using the
comparison stars as given by Romano a b On plates PX Cep was found
m
to b e fainter than : see Table As can b e stated from insp ection of the light curve
d
published by Boninsegna the star reaches this magnitude approximately : b efore
m
minimum Thus any detection of the target to b e fainter than : provides the time of
d
minimum within an accuracy of : this is ' : see dotted lines in Figure
Table Times of minima found on Sonneb erg plates HJD
In order to obtain the p erio d all data p oints of the orbital light curve were analysed
using the Analysis of Variance algorithm adopted from Schwarzenberg Czerny
The ep o ch was derived from the resulting O C values The following elements were
obtained
d
Min HJD : E
The O C curve for these elements is given in Figure Our own data are in agreement
with the assumption of a constant p erio d within the accuracy of the measurement The
three O C values b elow the con dence interval were measured by Romano From
the information provided in the literature it cannot b e decided with certainty what the
reason for these deviations might b e Two of these p oints obviously lie only on the shoulder
0.20
0.15
0.10
0.05
0.00 O-C (days) -0.05
-0.10
-0.15
-0.20 2436000 2438000 2440000 2442000 2444000 2446000 2448000 2450000
HJD
Figure O C for new elements Minima found on Sonneb erg plates are plotted with
diamonds star symbols are the times of minima as collected by Borovi cka The
m
dotted lines mark the width of the light curve b elow : as describ ed in text
m m m
of the minimum with magnitudes given as : and : The third one : cannot b e
explained assuming a constant p erio d Considering only the data collected by Borovi cka
a changing p erio d is indeed suggested but there is no convincing indication for that in
the Sonneb erg data
Even if the individual error of one single intensity measurement derived from a photo
graphic observation is quite large the sheer number of our measurements and moreover
the long time interval covered enable us to derive rather reliable elements that can explain
d
the b ehavior of PX Cep in the past years within an accuracy of ab out :
The author thanks Constanze la Dous for arranging this interesting pro ject and Peter
Kroll b oth Sonneb erg Observatory for lots of help
Claus HEERLEIN
Sternwarte Sonneb erg
Sonneb erg
Germany
ch sophia stw tu ilmenau de
References
Boninsegna R Inf Bul l Var Stars No
Borovi cka J Contrib Obs Brno No
Kholop ov P N et al Inf Bul l Var Stars No
Romano G a La Specola Ariel di Treviso
Romano G b Coelum
Romano G Publ Obser Astronom Padova No
Schwarzenberg Czerny A Mon Not Astr Soc
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
A NEW EPHEMERIS FOR ER CEPHEI
On June two of the authors RMB and RJH used the Southeastern
Asso ciation for Research in Astronomy SARA m telescop e at Kitt Peak National
Observatory to test the newly acquired Axiom Research Inc AX CCD camera equipp ed
with a Ko dak KAF chip Observations of the galactic cluster NGC
were made using a Cousins R lter The images were reduced using the MIRA Image
Pro cessing Software developed by Axiom Research Inc Di erential ap erture photometry
was p erformed resulting in light curves for ER ES EQ Cep and the variables V and V
de ned by Kaluzny Shara Our ER Cep light curve is shown in Figure Some
intrinsic night to night variations app ear to b e present A presentation and discussion of
all the observations will b e forthcoming After phasing the ER Cep data using the zero
ep o ch HJD and p erio d days listed in Kaluzny we noticed
p
that primary minimum o ccurred at phase This indicated the need to determine a
new ephemeris for ER Cep which we present in this note
Using the metho d of Kwee van Woerden one primary and two secondary
minima were determined from our observations We also computed minima from the
observations by Kaluzny Shara and Kaluzny These are listed in Table
together with estimates for their mean errors O C residuals are computed with
resp ect to the Kaluzny ephemeris The zero ep o chs listed in Worden et al
and Kholop ov Sharov were also added to the list as well as the minimum by
Kholop ov Sharov
Figure ER Cep di erential R magnitudes observed on June squares June
C
triangles and June diamonds
Figure O C diagram for ER Cep
A weighted linear least squares t to these minima yields the new ephemeris
Min HJD E
The residuals with resp ect to this ephemeris are listed as O C in Table and
shown plotted in Figure The orbital p erio d of ER Cep app ears to have remained
secularly constant over the past years This is unusual given the short p erio d of this
m
mo derately late sp ectral type B V W type W UMa binary
Table Minima for ER Cep
E O C HJD Error O C Reference
Kholop ov Sharov
Kholop ov Sharov
Worden et al
a
Kaluzny Shara
a
Kaluzny Shara
a
Kaluzny Shara
Kaluzny
Kaluzny
a
Kaluzny
Kaluzny
a
Kaluzny
this pap er
this pap er
this pap er
a
Determined in this pap er from observations listed in the reference
M E BELFORT P A FRIEND
R M BRANLY
W VAN HAMME
Department of Physical Sciences
Department of Physics
Broward Community College
Florida International University
Fort Lauderdale FL U S A
Miami FL U S A
R J HIGGINS
Motorola Inc
Radio Pro ducts Group Applied Research
Fort Lauderdale FL U S A
Acknowledgment Participants in the Research Exp erience for Undergraduates REU
program at Florida International University sp onsored by the National Science Founda
tion grant PHY
References
Kaluzny J AcA
Kaluzny J Shara M M ApJ
Kholop ov P N Sharov A S Astr Circ No
Kholop ov P N Sharov A S Astr Circ No
Kwee K K van Woerden H Bul l Astr Inst Netherlands
Worden S P Coleman G D Rucinski S M Whelan J A J MNRAS
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
PHOTOELECTRIC BVR OBSERVATIONS AND NEW ELEMENTS OF
C
THE CEPHEID HD
Recently Bastian et al and Camp os Cucarella et al published light curves
in B and V lters and light elements based on a short time span for the bright Cepheid
HD found by Makarov et al
To re ne the published ephemeris we have analysed photographic archival plates at
Sternberg Astronomical Institute of Moscow estimates and at Astronomical Insti
tute of Tashkent estimates We also observed HD photo electrically at Mt
Maidanak observatory in August where the cm re ector was used and BVR
c
measurements were obtained Table the accuracy of the individual data is near
mag in all lters According to our data the amplitude of the light curve Figure is
m m m
in V in B V and in V R c V HD 32456 P=3.294 7.2
7.8 B-V 0.9 1.1 V-R C 0.6 0.8
0.0 0.5 1.0
Figure
Table
JD hel Phase V B V V R JD hel Phase V B V V R
c c
− O C P HD 32456 C = 2433442.959+3.294747·E
0.1
0.0
0.1
2420000 30000 40000 JD
Figure
Table
Max JD hel Error Filter E O C Number
of observations
PG
PG
PG
PG
PV
PG
B
V
All observations obtained were analysed with Hertzsprung s metho d the derived ep o chs
of maxima are given in Table These ep o chs of maxima together with those published
by Bastian et al and Camp os Cucarella et al were introduced into a
linear least squares solution which resulted in the following improved ephemeris formula
Max JD hel E
This ephemeris was used in calculating the phases in Table and the O C values in
Table as well as for plotting our observations in Figure and O C diagram in Figure
where the ab ove mentioned published ep o ches of maxima are marked by crosses
The study describ ed in this publication was made p ossible in part by grants No
and No from the Russian Foundation of Basic Research
L N BERDNIKOV
O V VOZYAKOVA
V V IGNATOVA
Sternberg Astronomical Institute
Astronomical Institute
Universitetskij prosp
Astronomicheskaya ul
Moscow Russia
Tashkent Uzb ekistan
References
Bastian U Born E Agerer F Dahm M Grossmann V Makarov V IBVS
No
Camp os Cucarella F Guarro Flo J Gomez Forrelad J M Garcia Melendo E
IBVS No
Makarov V Bastian V Ho eg E Grossmann V Wicenec A IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
September
HU ISSN
PHOTOELECTRIC BVR OBSERVATIONS OF THE PECULIAR
c
CEPHEID V Lyr
V Lyr is classi ed as a Cepheid with variable amplitude in the GCVS So for the
study of the pulsation b ehaviour of this star it is very imp ortant to observe it as often
as p ossible
We observed V Lyr at Mt Maidanak observatory in August The cm
re ector was used and BVR measurements were obtained Table the accuracy of
c
the individual data is near mag in all lters According to our data the amplitude
of the light curve Fig is near mag in V
The phases are calculated with the elements
M axJ D hel E
The research describ ed in this publication was made p ossible in part by grants No
and No from the Russian Foundation of Basic Research
V V473 Lyr P=1.490 6.0 6.2 B-V 0.6 0.8 V-R C 0.4 0.6
0.0 0.5 1.0 Figure
Table
JD hel P hase V B V V R JD hel P hase V B V V R
c c
V V IGNATOVA
L N BERDNIKOV
Astronomical Institute
O V VOZYAKOVA
Astronomicheskaya ul
Sternberg Astronomical
Tashkent Uzb ekistan
Institute
Universitetskij prosp
Moscow Russia
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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September
HU ISSN
PHOTOELECTRIC BVR OBSERVATIONS
c
AND CLASSIFICATION OF NSV
Recently Antipin and Berdnikov found that NSV S GSC
h m s 0 00
Ep o ch was a Cepheid variable with light elements
M axJ D hel E
But it was di cult to de ne a type of this Cepheid b ecause there were no photo electric
observations then
We observed NSV at Mt Maidanak observatory in August The cm
re ector was used and BVR measurements Table were obtained The accuracy
c
of the individual data is near mag in all lters Light and color curves Figure
constructed with the ab ove elements show that NSV is obviously a CWA type
variable
Figure shows also that our observations do not satisfy the ab ove elements Using
the new ep o ch of maximum JD together with the published ones
Antipin and Berdnikov there are three variants of O C diagram due p ossible
miscalculation in the number of ep o chs Figure It is necessary to use plate collections
to ll in the gap b etween JD and in order to improve light elements
The research describ ed in this publication was made p ossible in part by grants No
and No from the Russian Foundation of Basic Research
V NSV 10183 P=13.63 11.5
12.1 B-V 0.9 1.1 V-R C 0.6 0.8
0.0 0.5 1.0 Figure
− − O C O C P NSV 10183 C = 2444942.37+13.6299·E P NSV 10183 C = 2444942.37+13.6299·E 0.6 0.0 0.4 0.2 0.2 0.0
2444000 46000 48000 JD 2444000 46000 48000 JD − O C P NSV 10183 C = 2444942.37+13.6299·E 1.6 1.2 0.8 0.4 0.0
2444000 46000 48000 JD
Figure
Table
JD hel P hase V B V V R JD hel P hase V B V V R
c c
L N BERDNIKOV
O V VOZYAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
V V IGNATOVA
Astronomical Institute
Astronomicheskaya ul
Tashkent Uzb ekistan
Reference
Antipin S V Berdnikov L N I B V S No
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COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
PHOTOMETRIC INVESTIGATION OF Y CANUM VENATICORUM
h m s
The carb on star Y CVn BD HD
0 00
was discovered as a variable star by Cannon Pickering Zverev
was the rst who determined a p erio dicity in its variations describ ed by the light elements
T E
max
The most systematic photometric investigation has b een carried out by Gap oshkin
who studied the star on plates of the Harvard Observatory taken at the b eginning of this
century He has found the p erio d P days Gap oshkin This is the p erio d
given in the General Catalogue of Variable Stars Kholop ov Gap oshkin derived the
m m m m
mean maximum brightness and the mean minimum brightness
m m
and the extreme maximum and minimum brightnesses and as well
Nevertheless the recent observations give evidence that mean p erio d is longer and the
character of the light variations is somewhat more complicated The star was observed
photo electrically by Dzervitis and Vetesnik from to Vetesnik estimated
the p erio d of the star P days and new light elements for the times of the minimum
T E
min
The BV photo electric observations of Y CVn presented in this pap er were p erformed
by Jiri Papousek at the Brno University Observatory in the course of the years
The photometer attached to the cm telescop e was equipp ed with an EMI
photomultiplier and its lter combinations ensured the measurements in the BV colours of
the Johnson standard photometric system The data reduction metho d was the standard
one The comparison star and the check one was HD and HD resp ectively
The mean standard deviation of one observation was b etter than mag most of them
even smaller than mag The total number of all observations was in V band
and in B band The original data will b e provided by the author up on request
The resulting light curves are plotted in Figures and The data used may represent
the longest continuous light curve of Y CVn obtained up to now
m
The data shows that mean maximum brightness of Y CVn and the mean minimum
m m m
brightness in V band while the corresp onding values are and in B band
m m
The extreme maximum and minimum brightnesses are and in V band and
m m m m
and in B band The colour index B V varies from to
After thorough treatment of data we have concluded
The p erio d of light variations determined by Date Comp ensated Discrete Fourier
Transform Kleczek is days 7.5
B [mag] 8
8.5
9
9.5
10
44000 45000 46000 47000 48000 49000 50000
JD-2 400 000
Figure The light curve of Y CVn in photometric band B b etween the years
The data have b een tted by the curve describ ed by the formula
5
5.2 V [mag]
5.4
5.6
5.8
6
6.2 44000 45000 46000 47000 48000 49000 50000
JD-2 400 000
Figure The light curve of Y CVn in photometric band V b etween the years
The data have b een tted by the curve describ ed by the formula
Table The co e cients of the light curves
band a mag a mag a mag a mag
V
B
There is a pronounced secular change
Some additional irregularities typical for this type of star are present
The observed variations of Y CVn can b e describ ed by secular change of the mean
brightness which may b e represented by a part of a parab ola sup erimp osed on nearly
sinusoidal variations of constant amplitude and the p erio d P days
Hence the light curve in particular colour may b e expressed by the following formula
with ve parameters
m a a E a E a sin E
where E JD P and is a phase shift of the zero p oint of the sinusoidal
hel
comp onent The co e cients have b een found using a sophisticated least squares metho d
Mikulasek The co e cients found for B and V colours are presented in Table
As is seen from Table the phase shifts in B a V band are not to o di erent so
we could consider them to b e the same and b eing equal to zero This conclusion is quite
natural from the physical p oint of view to o So we can write
m a a E a E a sin E
Acknowledgement I am thankful to Jiri Papousek for kindly providing me with his
observations of Y CVn and Zdenek Mikulasek for his help with the treatment of data
Jiri DUSEK
Nicholas Cop ernicus Observatory
Kravi hora
CZ Brno
Czech Republic
Internet dusek physics muni cz
References
Gap oshkin S Ann of Harv Col Obs
Kholop ov P N et al General Catalogue of Variable Stars Nauka Moscow
Kleczek J Exercises in Astronomy D Reidel Publishing Co
Mikulasek Z priv comm
Pickering E C HC No
Vetesnik M IBVS No
Zverev Sternberg Publ
COMMISSIONS AND OF THE IAU
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Number
Konkoly Observatory
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Octob er
HU ISSN
PHOTOELECTRIC MINIMA OF SOME ECLIPSING BINARIES
We present minima observations of eclipsing binaries not yet published any
where These stars were observed during several seasons and most of minima observations
are part of complete light curve coverages All observations were obtained with the
cm Maksutov telescop e at the Ankara University Observatory Di erential observations
were secured by using an EMI QB photomultiplier b efore September HJD
and an OPTEC SSP A photometer head which contains a side on R
Hamamatsu photomultiplier after that date The lters used are in close accordance with
the standard Johnson s UBV and reductions of the observations have b een p erformed in
the usual way Hardie
The moments of minima and their standard errors for each lter were calculated using
the metho d of Kwee van Woerden The algorithm of this metho d was applied
to the computer by M uyessero gluand G urol Weighted average values of times of minima
of these system are given in Table together with their minimum types lters and
observers Weighted averages and their mean errors for the minima times in di erent
lters were calculated with the formula given in G urol Selam
We give our sp ecial thanks to the observers for their helps during the observations
Zekeriya MUYESSEROGLU
Birol GUROL and
Selim O SELAM
Ankara University Observatory
Faculty of Science
TR Tando gan Ankara Turkey
References
G urol B Selam S IBVS No
Hardie R Astr Tech Stars and Stel lar Systems Vol I I Univ of Chicago Press
Chicago
Kwee K K van Woerden H Bul l Astron Inst Neth
Table Times of minima of observed systems
System Min HJD mean error Min Filter Observers
type
RT And II UBV Sl
I UBV Gr
I UBV Sl
II BV Gr
XZ And I UBV Gr
SS Ari I UBV My
I UBV Al
II UBV Sl
II BV My
I BV My
CK Bo o I UBV Hk
II UBV Od
I UBV My
I UBV Gr
KR Cyg I BV My
V Cyg II UBV Sl
I UBV Sl
II UBV Or
II UBV Kh
II UBV Sl
I UBV Od
I BV Od
II BV Sl
II BV Al
I BV Dn
I UBV Dr
II UBV Od
II UBV Al
RX Her I UBV Gr
II UBV Gr
TX Her I BV Sl
HS Her I UBV Od
II UBV My
I UBV Sl
II UBV Sl
I BV Sl
FG Hya I BV Sl
I UBV Or
II BV Or
II UBV Gr
I UBV Or
II BV My
I UBV Al
II UBV My
Table Continued
System Min HJD mean error Min Filter Observers
type
FG Hya I BV My
II BV My
I BV My
II BV My
II BV My
SW Lac II BV My
II BV Or
II BV Gr
I BV Gr
I BV Kh
I BV My
II BV My
II BV My
I BV Gr
II BV Gr
I BV My
II V My
I BV Od
I UBV Od
II UBV Od
I UBV Or
II UBV Or
II UBV My
I UBV My
II BV My
UV Leo I BV My
II UBV My
I UBV My
II BV Or
I BV Od
II BV Or
I BV Od
II UBV Gr
XY Leo II BV Or
I BV Or
I BV My
II BV My
II UBV Al
II UBV Sl
I UBV Ak
II BV Dn
I UBV Al
II BV My
Table Continued
System Min HJD mean error Min Filter Observers
type
V Oph II UBV Gr
I BV My
I UBV Gr
II BV Gr
II BV Gr
I UBV Gr
BB Peg I I UBV Od
I UBV My
I UBV Gr
II UBV Sl
DI Peg II BV Od
I UBV Sl
II BV Hk
II BV Ak
II V Dn
I UBV Ak
I UBV Gr
I UBV Gr
RT Per I BV Dr
II BV Yc
IQ Per I UBV Od
I UBV Ak
II UBV Sl
AQ Psc I UBV Dn
II UBV Od
II UBV Od
V Sgr I UBV Od
W UMa I UBV Sl
TX UMa I BV Sl
AW UMa I UBV Dr
II UBV Dr
II UBV Al
I UBV Dn
II UBV Al
I BV Ak
I BV Al
II BV Sl
AW UMa I UBV Al
HW Vir I BV Gr
I BV Gr
Observers
My Z M uyessero glu Sl S O Selam Gr B G urol
Ak A Akal n Dr I E Derman Or F F Ozeren
Dn H D undar Kh G Kahraman Od S Ozdemir
Al B Albayrak Yc K Y uce Hk H Ak
COMMISSIONS AND OF THE IAU
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Octob er
HU ISSN
NEW ELEMENTS OF V CYGNI
BAV Mitteilungen Nr
V Cyg S Cyg was discovered by Ho meister on photographic plates
of the Sonneb erg Observatory He classi ed the star as an Algol type variable in the
m m
range b etween : and : First investigation of this variable was p erformed by
Rohlfs She provided a photographic light curve reclassi ed the variable as
a W UMa type and determined rst elements as
d
Min I HJD : E
A few years later Romano investigated V Cyg again He derived minima
and improved the elements of Rohlfs as follows
d
Min I HJD : E
m m
Moreover Romano determined the range of variability b etween : and : phg
m m
in the primary and b etween : and : phg in the secondary minimum
With this data V Cyg is listed in the fourth edition of the GCVS Kholop ov et al
For a quarter of a century the variable had remained obviously unobserved when
we put V Cyg on our observing program The CCD observations were made with
SBIG ST cameras without lters attached to a cm RC telescop e W M and a cm
SC telescop e F A GSC served as comparison star and several other stars in
the same eld were used to check its constancy In our instrumental system the amplitude
m m
of variability is : for the primary minima and : for the secondary minima
A p erio d analysis program based on the algorithm of Schwarzenberg Czerny
showed that the p erio d given in the GCVS is a spurious one with the relation
0
p p
Using all available minima a weighted least squares t led to the new elements
d
Min I HJD : E
All our times of minimum light were determined with the Kwee van Woerden metho d
Figure Di erential light curve of V Cyg drawn with the new ephemeris
Figure O C diagram for V Cyg using the new ephemeris
represents photo electric photographic series visual observations and 2 photo graphic plate minima
Table Observed times of minima for V Cyg ep o chs and residuals computed with
resp ect to the linear ephemeris derived in this pap er
? ?
JD hel W T Ep o ch O C Lit JD hel W T Ep o ch O C Lit
P V
P V
P P
P P
P P
P P
P P
P P
P P
P P
P P
P F
P F
P F
P F
P E
P E
P E
P E
P E
V E
V E
V E
V E
V E
V E
V
?
P denotes photographic minima V visually observed
E CCD observed minima and F photographic series
Those marked with got reduced weight
E Rohlfs VSS C Ho meister VSS G Romano MSAI
W Moschner W Kleikamp BAVM No W Moschner W Kleikamp BAVM No
W Moschner BAVM No W Moschner this pap er F Agerer this pap er
The individual measurements can b e requested and will b e sent via e mail
F AGERER
W KLEIKAMP
W MOSCHNER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm
D Berlin Germany
E mail
agerer zweik t online de
wilhelm kleikamp t online de wolfgang moschner t online de
References
Ho meister C Erg AN
Kholop ov P N et al General Catalogue of Variable Stars th Edition Nauka
Moscow
Kwee K K van Woerden H Bul l Astr Inst Netherlands
Rohlfs E Mitteilungen uber ver anderliche Sterne Sonneberg No
Rohlfs E Ver o entlichungen der Sternwarte zu Sonneberg
Romano G Asiago Contr No
Schwarzenberg Czerny A Monthly Notices R Astr Soc
EDITORS NOTE
Mr Anton Paschke called our attention that the new RR Lyrae type variable GSC
discovered by Gladders and Robb see IBVS No is identical with the new variable
No discovered by Antipin IBVS No The two notes have b een published so
close in time that they are undoubtedly indep endent discoveries
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
PHOTOELECTRIC MINIMA AND MAXIMA OF SELECTED
ECLIPSING AND PULSATING VARIABLES
BAV Mitteilungen No
In this th compilation of BAV results photo electric observations obtained in the
years and are presented on variable stars giving minima and maxima
All times of minima and maxima are helio centric The error of margins are tabulated
in column The values in column O C are determined without incorp oration of
nonlinear terms The references are given in the section remarks All information ab out
photometers and lters are sp eci ed in the column Rem The observations were made
at private observatories and the public observatory of N urnberg The photo electric mea
surements and all the lightcurves with evaluations can b e obtained from the o ce of the
BAV for insp ection
Table Eclipsing binaries
Variable Min JD = Ph Obs O C GCVS Rem
KP Aql L BK : s GCVS
OO Aql L BK : s GCVS
V Aql L KI : GCVS
V Aql L KI : GCVS
V Aql L KI : GCVS
V Aql L AG : s GCVS
L AG : GCVS
L AG : s GCVS
V Aql LV AG : GCVS
LB AG : GCVS
L KI : GCVS
AR Aur L BUS : s GCVS
IM Aur LV AG : GCVS
LB AG : GCVS
LB AG : GCVS
LV AG : GCVS
KO Aur L AG : GCVS
MN Aur L MS : s GCVS
L MS : GCVS
XY Bo o L KI : GCVS
AC Bo o LV AG : s GCVS
LB AG : s GCVS
Table cont
Variable Min JD = Ph Obs O C GCVS Rem
TU Cam LB AG : GCVS
AW Cam LB AG : GCVS
LV AG : GCVS
BI CVn LB AG : s GCVS
LV AG : s GCVS
LV AG : GCVS
LB AG : GCVS
LV AG : s GCVS
LB AG : s GCVS
LB AG : GCVS
LV AG : GCVS
BO CVn LV AG
LB AG
BH CMi LV AG
LB AG
GT Cas L MS : GCVS
OX Cas LB AG : s GCVS
LV AG : s GCVS
V Cas L MS : GCVS
AH Cep LB AG : s GCVS
LV AG : s GCVS
CW Cep LB AG : GCVS
LV AG : GCVS
LV AG : s GCVS
EF Cep L AG : GCVS
L AG : s GCVS
L AG : s GCVS
EM Cep LB AG : GCVS
LV AG : GCVS
RW CrB LV AG : GCVS
LB AG : GCVS
TX Her L BK : GCVS
AK Her L BK : s GCVS
SW Lac L BK : s GCVS
L BK : s GCVS
L FR : s GCVS
L FR : GCVS
V Lac L FR : GCVS
V Oph L KI : GCVS
V Oph L KI : GCVS
V Oph L KI : GCVS
V Oph L KI : GCVS
CP Ori L MS : GCVS
ER Ori L KI : s GCVS
U Peg L KI : s GCVS
BB Peg L KI : GCVS
L KI : GCVS
BN Peg L KI : GCVS
BO Peg L KI : GCVS
DI Peg L KI : GCVS
GH Peg L KI : GCVS
HW Vir L HAS DEI
Table RR Lyrae Delta Scuti type stars
Variable Max JD = Ph Obs O C GCVS Rem
BK And L BK : GCVS
DK And L BK : GCVS
SX Aqr L KI : BAVM
CY Aqr L KI : GCVS
L KI : GCVS
V Aql L BK : GCVS
V Aql L KI : GCVS
RV Ari L BK : GCVS
L BK : GCVS
RW Ari L BK : GCVS
AH Cam L BK : GCVS
VW CVn L AG : BAVM
L AG : BAVM
L AG : BAVM
L AG : BAVM
L AG : BAVM
L AG : BAVM
L AG : BAVM
L AG : BAVM
X CMi L PS : GCVS
L PS : GCVS
AA CMi L PS : GCVS
HY Com L MS
SZ CrB L MS : GCVS
L MS : GCVS
XZ Cyg L BK : GCVS
DM Cyg L BK : GCVS
DX Del L KI
EG Del L KI : GCVS
SW Dra LV WU GZI : GCVS
LV WC : GCVS
LV WU MSL : GCVS
LV WU GZI : GCVS
LV WU TRB : GCVS
VZ Dra L BK : GCVS
L BK : GCVS
XZ Dra L BK : GCVS
RT Equ L PS : GCVS
BK Eri L KI
SZ Gem L BK : GCVS
KV Gem L BK : GCVS
VZ Her L BK : GCVS
DL Her L KI : GCVS
DY Her L KI : GCVS
LS Her L KI : GCVS
CZ Lac L BK : GCVS
ST Leo L KI : GCVS
AA Leo L PS : GCVS
EH Lib L KI : GCVS
RW Lyn L BK : BAVM
TV Lyn L BK : GCVS
RZ Lyr L BK : GCVS
Table cont
Variable Max JD = Ph Obs O C GCVS Rem
V Oph L KI : GCVS
VV Peg L KI : GCVS
VZ Peg L BK : GCVS
BF Peg L BK : GCVS
BP Peg L PS : GCVS
L BK : GCVS
DH Peg L BK : GCVS
L BK : GCVS
L KI : GCVS
DY Peg L KI : GCVS
L KI : GCVS
KN Per L BK : GCVS
RU Psc L BK : GCVS
L BK : GCVS
L BK : GCVS
RY Psc L BK : GCVS
SS Psc L BK : GCVS
L BK : GCVS
L KI : GCVS
L BK : GCVS
CW Ser L KI : GCVS
BC Vir L KI : GCVS
R e m a r k s
AG Agerer F Zweikirchen MS Moschner W Lennestadt
BK Birkner C Hagen MSL Meisel S N urnberg
BUS Busch H Hartha MSR Moschner J Lennestadt
DEI Deininger H Karlsruhe PS Paschke A Rueti CH
FR Frank P Velden TRB Traub J N urnberg
GZI Garzarolli M Ho echstadt WC Wieck M N urnberg
HAS Hase F Karlsruhe WU Wunder E Heidelb erg
KI Kleikamp W Marl
uncertain
s secondary minimum
L photo electric observation without lter
LB as ab ove lter B
LV as ab ove lter V
photometer P lter V GG B BG GG
photometer Schnitzer
photometer CCD x uncoated without lter
photometer EMI A lter V GG mm B BG mm GG mm
photometer Cryocam A without lter
photometer ST without lter
GCVS nn Gen Cat of Variable Stars th ed
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No
Franz AGERER
Joachim HUBSCHER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm D Berlin Germany
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
PHOTOELECTRIC MINIMA OF SELECTED ECLIPSING BINARIES
BAV Mitteilungen No
In this th compilation of BAV results photo electric observations obtained in the
years and are presented on variable stars giving minima All times of
minima are helio centric The error of margins is tabulated in column The values in
column O C are determined without incorp oration of nonlinear terms The references
are given in the section remarks All information ab out photometers and lters are
sp eci ed in the column Rem The observations were made at private observatories
and the public observatory of N urnberg The photo electric measurements and all the
lightcurves with evaluations can b e obtained from the o ce of the BAV for insp ection
Table Eclipsing Binaries
Variable Min JD = Ph Obs O C GCVS Rem
V Aql L KI : s BAVR
V Aql L KI : GCVS
L MSR : GCVS
AH Aur L AG : s BAVR
AP Aur L MS : BAVM
LB AG : s BAVM
LV AG : s BAVM
GX Aur L MS : BAVM
L MS : BAVM
L MS : s BAVM
TY Bo o L MS : BAVM
TZ Bo o L AG : s BAVM
L AG : BAVM
VW Bo o L MS : BAVR
FF Cnc LV AG : s BAVM
LB AG : s BAVM
V Cas L MS : BAVM
WW Cep L AG : s BAVM
SS Com L AG : BAVR
UX Com L MS MSR : BAVM
CC Com L KI : GCVS
DK Cyg LB AG : BAVR
LV AG : BAVR
GO Cyg LB AG : GCVS
LV AG : GCVS
Table cont
Variable Min JD = Ph Obs O C GCVS Rem
GO Cyg LV AG : s GCVS
LB AG : s GCVS
V Cyg LV AG : GCVS
LB AG : GCVS
V Cyg LV AG : GCVS
LB AG : GCVS
V Cyg LV AG : GCVS
LB AG : GCVS
V Cyg LV AG : GCVS
LB AG : GCVS
V Cyg LV AG : s BAVR
V Cyg LV AG : GCVS
LB AG : GCVS
V Cyg L AG : s GCVS
L AG : GCVS
V Cyg LB AG
LV AG
LB AG
TT Del L KI : GCVS
TY Del L KI : GCVS
YY Del L KI : GCVS
EX Del L AG : GCVS
L KI : GCVS
FZ Del L KI : GCVS
GG Del L KI : GCVS
BX Dra L AG : s GCVS
CV Dra LV AG : BAVM
LB AG : BAVM
EF Dra LB AG : BAVM
LV AG : BAVM
UX Eri L KI : GCVS
L KI : GCVS
YY Eri L KI : GCVS
L KI : s GCVS
BL Eri L KI
BV Eri LV AG : s GCVS
LV AG : s GCVS
LV AG : s GCVS
LV AG : GCVS
UX Her L KI : GCVS
CT Her L KI : GCVS
HS Her LB AG : s GCVS
LV AG : s GCVS
LV AG : GCVS
PW Her LB AG : BAVM
LV AG : BAVM
AV Hya LB AG : GCVS
LV AG : GCVS
LB AG : GCVS
LV AG : GCVS
FG Hya LV AG : s GCVS
LB AG : s GCVS
EM Lac L AG : GCVS
Table cont
Variable Min JD = Ph Obs O C GCVS Rem
UZ Leo L MS : s GCVS
L AG : s GCVS
VZ Leo L KI : GCVS
XY Leo LB AG : GCVS
LV AG : GCVS
LV AG : GCVS
LB AG : GCVS
LB AG : GCVS
LV AG : GCVS
XZ Leo LV AG : GCVS
LB AG : GCVS
LB AG : GCVS
LV AG : s GCVS
LB AG : s GCVS
AG Leo L AG : GCVS
AL Leo L MS : BAVM
LV AG : s BAVM
LB AG : s BAVM
LB AG : s BAVM
LV AG : s BAVM
AP Leo L KI : GCVS
RT LMi L MS : GCVS
L MS MSR : s GCVS
L MS : s GCVS
L MS : GCVS
V Lyr L MS MSR : s GCVS
L MS : GCVS
L MS : GCVS
L MS : GCVS
V Lyr L AG : BAVM
AQ Mon L KI : GCVS
NS Mon LB AG : s BAVM
LV AG : s BAVM
L KI : s BAVM
V Mon L MS : GCVS
L MS : s GCVS
L MS : GCVS
BP Per L AG : s GCVS
L AG : GCVS
IM Per L MS : GCVS
L MS : GCVS
L AG : GCVS
V Per L MS : GCVS
V Per LV AG : BAVM
LB AG : BAVM
L MS : BAVM
L MS : BAVM
VZ Psc L KI : s GCVS
CU Sge L KI : GCVS
CW Sge LB AG : GCVS
LV AG : GCVS
LB AG : s GCVS
LV AG : s GCVS
Table cont
Variable Min JD = Ph Obs O C GCVS Rem
RS Sct L KI : GCVS
CC Ser L KI : GCVS
GR Tau L AG : BAVR
LV AG : s BAVR
LB AG : s BAVR
UY UMa L AG : s GCVS
L AG : GCVS
AX Vir L KI : BAVR
AZ Vir L KI : GCVS
BK Vul L MS : GCVS
R e m a r k s
AG Agerer F Zweikirchen MS Moschner W Lennestadt
KI Kleikamp W Marl MSR Moschner J Lennestadt
uncertain
s secondary minimum
L photo electric observation without lter
LB as ab ove lter B
LV as ab ove lter V
photometer CCD x uncoated without lter
photometer EMI A lter V GG mm B BG mm GG mm
GCVS nn Gen Cat of Variable Stars th ed
BAVM nn BAV Mitteilungen No nn
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No IBVS No
BAVM BAV Mitteilungen No IBVS No
BAVR BAV Rundbrief
BAVR BAV Rundbrief
BAVR BAV Rundbrief
BAVR BAV Rundbrief
BAVR BAV Rundbrief
Franz AGERER
Joachim HUBSCHER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm D Berlin Germany
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
PHOTOMETRY OF RT ANDROMEDAE
RT Andromedae BD A in the catalog of Strassmeier et al
is a member of the short p erio d eclipsing group of RS CVn stars Zeilik et al
mo deled the sp ot structure for available data from to and reviewed previous
work Heckert mo del the sp ots on RT And during Building on the ab ove
work we mo del the sp ot structure during We observed RT And on the nights of
and January using the San Diego State University cm telescop e on
Mt Laguna We used the same instrument technique and calibration as describ ed by
Heckert The light curves contain a few gaps most noticeably just b efore the
eclipses and during the rst half of the primary eclipse The data are however su cient
to mo del the sp ots Figures and show di erential magnitudes star comparison
in the standard Johnson Cousins system The data are available in digital form from
PAH Budding and Zeilik describ e in detail the Information Limit Optimization
Technique ILOT that we used to mo del the data We p erformed the initial ts starting
with the orbital parameters found by Zeilik et al Unlike most of the short p erio d
RS CVns RT And has an elliptical orbit However we were unable to t the ellipticity
parameters and kept them xed at the initial values From the initial ts we extracted
a distortion wave and t it to the longitude and radius of a single circular sp ot at K
With the exception of the B band we were unable to t for the latitude simultaneously
with the other parameters and used a xed latitude of The ts for each wavelength
are p erformed indep endently We get
Sp ot Fits
B band V band R band I band
Longitude
Latitude
Radius
2
Figures and show the initial and sp ot ts in the V band We did not attempt
to do clean ts to remove the sp ot e ects and nd the binary star parameters b ecause
the incompleteness of the primary eclipse would reduce the con dence in such solutions
These results are similar to the previous long term trend found by Zeilik et al
A single sp ot in one of two Active Longitude Belts ts the data well Comparing these
results to those of Heckert we nd that the sp ot in was roughly the same
size as in but was in the opp osite active longitude b elt We also note that in
the sp ot was near the edge of the active longitude b elt In b oth this and previous
work the sp ots seem to b e at middle latitudes but the latitude ts generally have low
con dence and were usually xed at rather than t to the data
Figure RT And B and V light curves
Figure RT And R and I light curves
Figure RT And V band initial t
Figure RT And V band sp ot t
We thank Ron Angione for scheduling very generous amounts of observing time at Mt
Laguna PAH acknowledges supp ort from the Cottrel College Science Program of the
Research Corp oration MRB and KP acknowledge supp ort from the Summer Ventures in
Science and Mathematics Program at Western Carolina University
PAUL A HECKERT
Dept of Chem Physics
Western Carolina University
Cullowhee NC USA
MELINDA R BEAVER
Summer Ventures Program
Western Carolina University
and Alexander Central High School
Taylorsville NC USA
KELLY PHILLIPS
Summer Ventures Program
Western Carolina University
and Wilkes Central High School
Wilkesboro NC USA
References
Budding E and Zeilik M Astrophys J
Heckert P A Inf Bul l Var Stars No
Strassmeier K et al Astron Astrophys Suppl
Zeilik M Cox D A De Blasi C Rho des M and Budding E Astrophys J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
XZ Lac NSV
During the preparation of nding charts for many neglected RR Lyr type variable stars
lo cated in the northern hemisphere I have found that the susp ected variable NSV
coincides in p osition with XZ Lac This star is listed in the GCVS Kholop ov et al
as a member in the RRAB sub class with a range of variation P and with the
following co ordinates
h m s 0
R A Decl :
these values can b e precessed to the ep o ch as follow
h m s 0
R A Decl :
the most recent information ab out XZ Lac was published by Gessner
NSV was discovered by Brun during the analysis of the photographic
investigation of the stars in the Lac eld carried out by Weber In his pap er Brun
listed NSV as the No of his own catalogue of newly discovered variables and
classi ed it as a susp ected RR type star with a range of variation P for the
ep o ch he gave the following co ordinates
h m s 0
R A Decl :
precessed to the ep o ch b eing
h m s 0
R A Decl :
No nal designation was accepted for Brun and on the basis of these pieces of
information it was included in the NSV Catalogue Kholop ov et al Checking
literature on variable stars I could not nd any other publication on NSV than
Brun s pap er
Figure Identi cation charts for XZ Lac left and NSV right
Figure Field of XZ Lac NSV GSC printed from the Guide Star
Catalogue
The identi cation chart for XZ Lac quoted in the GCVS Kholop ov et al was
published by Ho meister but the original work was not available for me so for the
purp oses of the present study I used the chart published by Tsesevich and Kazanasmas
repro duced in Figure together with the nding chart published by Brun
for NSV Comparing these two charts it seems clear that XZ Lac is identical with
NSV
The third chart presented here see Figure shows the same eld repro duced from
the Guide Star Catalogue GSC
The star marked b etween two lines is GSC and it coincides with XZ Lac
the following co ordinates for the ep o ch are given
h m s 0 00
R A : Decl :
Massimiliano MARTIGNONI
Via Lonate Pozzolo n
I Busto Arsizio Italy
References
Brun A Journal des Observateurs No
Gessner H Ver o der Sternw Sonneberg H
Ho meister C Mitteil der Sternw Sonneberg Nr
Kholop ov P N et al New Catalogue of Susp ected Variable Stars Moscow Nauka
Publishing House
Kholop ov P N et al General Catalogue of Variable Stars Moscow Nauka
Publishing House
Tsesevich V P Kazanasmas M S Atlas of Finding Charts of Variable Stars Moscow
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
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Octob er
HU ISSN
NSV FIRST ELEMENTS AND LIGHTCURVE
BAV Mitteilungen Nr
NSV SVS was discovered by Kuro chkin in an investigation of new
h m
variables on photographic plates of the eld SA centered at
In this search new variables were found with SVS among them It was clas
m
si ed as a p ossibly RR Lyrae type variable with a brightness range b etween : and
m
: An identi cation chart was given but no light curve Since elements were not pub
lished SVS is listed as NSV in the New Catalogue of Susp ected Variable Stars
Kholop ov et al
Almost years later we put NSV on our observing program The CCD obser
vations were made with SBIG ST cameras without lters attached to a cm Ritchey
Chretien telescop e with f mm W Moschner and a cm astrograph with f
mm P Frank The integration time was seconds at the RC telescope and
seconds at the astrograph Our CCD observations cover days
The shap e of the light curve reveals NSV surprisingly as variable of Lyrae
type Figure All minima times were calculated with the Kwee van Woerden metho d
Kwee van Woerden In the instrumental system of our CCD observations the depth
m m
of the primary and the secondary minima were found to b e : and : resp ectively
Based on our conclusion that NSV is of Lyrae type we reinterpreted Kuro chkin s
m
individual estimations in the following way Each observation fainter than : was
considered to b e a minimum Weighting CCD minima times higher than Kuro chkin s
photographic data we obtained the following ephemeris
d
Min I HJD : E
The resulting O C diagram Figure shows a large scattering of the photographic
data This is caused by the interpretation of dim magnitudes as minima the related
moments may not b e the exact minima times as well as the rather long exp osure times
of the photographic plates not given by Kuro chkin but we assume some minutes
compared to the short p erio d of the star
Figure Identi cation chart for NSV A comparison B and check star C The
size of the frame is arcmin North is on top
Figure Di erential light curve of NSV computed with resp ect to the rst elements
Table Observed times of minima for NSV 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
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
E
E
E
E
E
E
E
E
?
E denotes CCD observed maxima P are photographic W relative weight
Kuro chkin
P Frank this pap er
W Moschner this pap er
0.06
0.04
0.02
0 O-C [d]
-0.02
-0.04
-0.06 15000 20000 25000 30000 35000 40000 45000 50000 55000
JD - 2400000
Figure O C diagram of NSV photographic minima by Kuro chkin
CCD by the authors
P FRANK
J MOSCHNER
W MOSCHNER
E mail
wolfgang moschner t online de
Bundesdeutsche Arb eitsgemeinschaft
f ur Ver anderliche Sterne e V
BAV
Munsterdamm
D Berlin Germany
References
Kholop ov P N et al New Catalogue of Susp ected Variable Stars
Kuro chkin N Variable Stars
Kwee K K van Woerden H Bul l Astr Inst Netherlands
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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Octob er
HU ISSN
NEW EPHEMERIS AND LIGHT CURVES OF DD MONOCEROTIS
The rst ephemeris of DD Mon HD was given by Ahnert et al Wach
mann later published a photographic light curve and obtained a revised ephemeris
d
Min I HJD : E
Yamasaki et al gave the rst photo electric light curves but they did not publish
their times of light minima They used Wachmann s light elements to compute the phases
p
of their observations and applied the correction of : in their analysis
New photo electric observations of DD Mon were carried out with the m telescop e
at Yunnan Observatory Academia Sinica during seven nights in January and February
The B and V lters approximate Johnson s standard UBV system HD
and HD were chosen as comparison and check stars resp ectively the same stars
were used by Yamasaki et al Nightly extinction co e cients were determined
from the observations of the comparison star The observational accuracy throughout the
observing p erio d as derived from the magnitude di erence b etween the check star and the
m m
comparison star is : V and : B Altogether V observations and B
observations have b een obtained for DD Mon
From Yamasaki et al s and our observations seven times of light minima have b een
determined by using quadratic tting metho d and have b een listed in Table All
available times of light minima were introduced into a least squares solution to derive the
new ephemeris
d
Min I HJD : E
In Table the O C residuals were calculated by using this new formula and the
O C were calculated by using Wachmann s ephemeris The determined light minima
are to o few to study the p erio d change of the system More observations for DD Mon are
necessary to know the p erio d b ehaviour of this binary
Table Moments of light minima and O C residuals of DD Mon
JD Hel Filter Min O C O C
B V II
B V I
B V II
B V I
B V I
B V I
B V I
The rst four times of minima were determined from Yamasaki et al s observa tions
Figure B and V light curves of DD Mon The op en circles show the present
observations and the lled circles indicate Yamasaki et al s observations in and
The light variations of DD Mon relative to HD in the sense variable minus com
parison are shown in Figure as op en circles The lled circles indicate the
observations published by Yamasaki et al The maximum brightness of our light
m m
curves was fainter by : B and : V and the minimum brightness was also fainter
m m
by : B and : V as compared with the observations The photomet
ric asymmetries O Connell e ect on Yamasaki et al s light curves are not seen
on our light curves The photometric disturbances b etween phases on their light
curves were shifted to phases The variation of the light curves may b e caused
by the evolution of the system and or the stellar activity The light curve analysis using
WD synthesis metho d will b e published elsewhere
QIAN SHENGBANG
LIU QINGYAO
YANG YULAN
GU SHENGHONG
HUANG ZHANQUI
Yunnan Observatory
Chinese Academy of Sciences
Kunming
P R China
References
Ahnert P Ho meister C Rohlfs E and van de Voorde A Ver o Sternw
Sonneberg No
Wachmann A A Astron Abh Hamburger Sternw Bergedorf No
Yamasaki et al Astron J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
Octob er
HU ISSN
THE PERIOD BEHAVIOUR OF BL ERIDANI
The ephemeris of BL Eri given in the General Catalogue of Variable Star Kholop ov
et al is
d
Min I HJD E
Later from the rst photo electric observations Kern and Bo okmyer improved
the ephemeris as
d
Min I HJD E
The orbital p erio d of the system has b een discussed in various studies Yamasaki et
al susp ected that the orbital p erio d of BL Eri likely changed b etween and
Recently Qingyao et al p ointed out that the orbital p erio d increased but
prop erty of the p erio d changes is unclear
The eclipsing binary BL Eri was observed in January with the m telescop e at
Yunnan Observatory in China BD and BD were chosen as the com
parison and check stars resp ectively From our observations two moments of secondary
minima were determined which are listed in Table
With the ephemeris given by Kern and Bo okmyer we have computed the
O C values of a number of times of minima we found in references and have listed in
Table Using these O C values we derived the O C diagram displayed in Figure
In Figure a systematic trend is seen the p erio d has b een increasing continuously In
order to determine the rate of p erio d change all the minimum times were introduced into
a quadratic least squares solution which resulted in
d d
Min I HJD E E
and the rate of p erio d change dP dE day With this latter ephemeris
we computed the O C values in Table Comparing the O C values with the
O C values in Table the quadratic ephemeris has smaller deviation
Table Moments of minimum light of BL Eri
JD Hel Error day Min Filters
II B V
II B V
Figure The O C diagram plotted using the linear ephemeris the solid curve
represents the quadratic t
Table
JD Hel E O C O C Source
1 2
Kern and Bo okmyer
Kern and Bo okmyer
Kern and Bo okmyer
Kern and Bo okmyer
Yamasaki et al
Yamasaki et al
Yamasaki et al
Qingyao et al
Qingyao et al
Present pap er
Present pap er
than the linear one this p oint could also b e seen from the sums of square of the
X X
deviations
W W
O C O C
2 1
i i
i i
QIAN SHENGBANG
LIU QINGYAO
YAN YULAN
GU SHENGHONG
HUANG ZHANQUI
Yunnan Observatory
Chinese Academy of Sciences
Kunming
P R China
References
Kern J R Bo okmyer B B IBVS No
Kholop ov P N et al The General Catalogue of Variable Star th ed Nauka
Moscow
Qingyao Liu et al A Ap Suppl Ser
Yamasaki A et al A J
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC BVI OBSERVATIONS AND NEW ELEMENTS
C
FOR THE RR LYRAE STAR SU Col
SU Col was included in our program of photo electric observations for Cepheids b ecause
it is classi ed in GCVS IV as a type II Cepheid with a p erio d of P days We
observed the star at CTIO in September and Octob er using the m re ector A
total of BVI measurements were obtained Table the accuracy of the individual
c
m
data b eing near in all lters
As observations were accumulated it b ecame clear that SU Col is not a Cepheid
Gessner suggested previously that SU Col is an RR Lyrae star with the elements
Max JD E
hel
Those elements are used in Figure for plotting our new observations The data
indicate that SU Col is indeed an RR Lyrae variable and that the amplitude of the light
m m m
curve is at present in V in B V and in V I while the ep o ch of
c
maximum light is JD
V SU Col P=0.487361 12.1
12.9 B-V 0.2 0.4 V-I C 0.3 0.5
0.0 0.5 1.0 Figure
Table
JD V B V V I JD V B V V I
hel c hel c
M axJ D Uncertainty E O C
hel
− O C P SU Col C = 2450363.87+0.48735842·E
0.2
0.1
0.0
2430000 40000 JD Figure
The slight o set in phase of the light curve in Figure implies that Gessner s elements
do not satisfy our observations In order to derive a more reliable p erio d we searched
Gessner s data for times near maximum photographic brightness and combined the ep o chs
with the present results Two ep o chs taken from Gessner s data app ear to lie very close to
true light maximum since the star was brighter at those times than at others Those ep o chs
d
were assigned an uncertainty of while the remaining instants near maximum
photographic brightness published by Gessner were assigned an uncertainty of
d
Table The latter app ear to b e displaced slightly towards the declining light
p ortion of the light curve and result in the somewhat skewed distribution of data p oints
in the O C diagram Figure A linear least squares analysis of the resulting O C
data with weights inversely prop ortional to the squares of the asso ciated uncertainties
gave the following improved ephemeris
Max JD E
hel
The new elements were used to calculate the O C values listed in Table
The research describ ed here was made p ossible in part by grants No and
No from the Russian Foundation of Basic Research to LNB and through
NSERC Canada to DGT The authors were Visiting Astronomers at Cerro Tololo Inter
American Observatory National Optical Astronomy Observatories which is op erated
by the Asso ciation of Universities for Research in Astronomy Inc AURA under co
op erative agreement with the National Science Foundation
L N BERDNIKOV
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
D G TURNER
Saint Mary s University
Halifax Nova Scotia B H C
Canada
Reference
Gessner H Mitt Ver anderl Sterne Sonneberg
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOMETRIC AND POLARIMETRIC OBSERVATIONS
OF SEVEN MIRAS
Photometric and p olarimetric observations of red giants and sup ergiants have b een
carried out at the Byurakan Astrophysical Observatory since In Magnan
suggested to include in that program systematic photometric observations of Mira Ceti
type long p erio d variables Preliminary results of those observations are given in this
pap er
Seven long p erio d Mira type variables were observed in Byurakan Observatory dur
ing April September The observations have b een made with the photop olarimeter
attached to the AZT cm telescop e That photop olarimeter works in the regime of
intensi cation of the direct current It can b e used either as a photo electric photome
ter without the p olaroid or as a photop olarimeter with the p olaroid The maximum
of sensitivity of the photomultiplier lies in the wavelength interval A The
observations have b een done in the U B V R bands sometimes without the lter l
ter A more detailed description of the metho d and instruments has already b een
given elsewhere Eritsian and Nersisian
The results of p olarimetric observations for the Mira variables are presented in Table
The columns of the table successively give i the name of the star from the General
Catalogue of Variables Stars GCVS ii the date of the observation iii the observed
degree of p olarization P in the U B V R bands when the observations have b een done
without any lter this is indicated by the term lter and iv the angle of p olarization
The uncertainties in the photometric and p olarimetric measurements resp ectively are
m m
UBV The uncertainty in the determination of
UBV P
the p olarization angle is
As can b e seen from Table a light p olarization has b een detected for the stars R Aql
RT Cyg and S UMi In those three cases the variable character of the p olarization has
b een con rmed
As a noteworthy result a rapid light variation of the star T Cep has b een found ab out
two months after the maximum of brightness The corresp onding data in the B and V
bands are given in Table The light variations are drawn in Figure The solid straight
line represents the mean light curve in V color which has b een obtained from the data
of the GCVS by knowing the ep o ch of maximum and the phase One can see that
the whole event lasted less than days but the duration of the p eak itself represents
only a few days
Table Polarimetric observations of Mira Ceti type stars
star date P
GCVS UT U B V R U B V R
R Aql lter
T Cep
RT Cyg
R Dra
X Oph
S UMi
R Vir
Table Rapid variation of T Cep
Date B V
May
May
May
June
6
T Cep V
7
8 B magnitude
9
50 60 70 80
days (after the maximum)
Figure Rapid variation of T Cep
Acknowledgements One of the authors Melikian is very grateful to Drs Christian
Magnan and Marie Odile Mennessier for their hospitality and the p ossibility they gave him
to work in the Montpellier University He duly acknowledges the supp ort of the direction
of the PICS which co ordinates the French Armenian collab oration in astronomy
at the national level He is also much indebted to the University of Montpellier for its
nancial supp ort in the framework of the exchanges with the University of Erevan
C MAGNAN
M O MENNESSIER
GRAAL Universit ede Montpellier I I
France
e mail magnan graal univ montp fr
N D MELIKIAN
M H ERITSIAN
A A KARAPETIAN
Byurakan Astrophysical Observatory
Armenia
e mail byurakan pnas sci am
Reference
Eritsian M A Nersisian S E Astro zika
ERRATUM
In IBVS No issue Table contains incorrect data on the minima of V Cen
The revised table is as follows
JD Hel Eclipse Type Cycles O C O C
I
I
J D GRAY
S WOISSOL R G SAMEC
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
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November
HU ISSN
NEW TYPE AND ELEMENTS FOR V CYGNI
BAV Mitteilungen Nr
V Cyg S Cyg was discovered by Ho meister on photographic plates
of the Sonneb erg Observatory The rst investigation of this variable was p erformed by
Gessner on photographic plates taken with the Heidelb erg Bruce Astrograph in
the years and and with Sonneb erg astrographs after She classi ed the
m m
variable as a W UMa type in the range b etween : and : and determined rst
elements as
d
Min I HJD : E
With these data V Cyg is listed in the fourth edition of the GCVS Kholop ov
et al Since then the variable has not b een observed until we put V Cyg
on our observing program The observations were made with SBIG ST CCD cameras
without lters attached to a cm RC telescop e W M and a cm SC telescop e F A
GSC served as comparison star and several other stars in the same eld were
used to check its constancy The individual measurements can b e requested via e mail
Figure Di erential light curve of V Cyg drawn with the new ephemeris
Table Helio centric times of CCD measured maxima for V Cyg ep o chs and
residuals computed with resp ect to the ephemeris derived in this pap er
JD hel Ep o ch O C Observer
Moschner
Moschner
Agerer
Agerer
Agerer
Moschner
Moschner
Moschner
Agerer
A p erio d analysis program based on the algorithm of Schwarzenberg Czerny re
sulted in a p erio d much shorter than the GCVS p erio d As our CCD observations show
the variable is of RR Lyr type see Figure In our instrumental system the amplitude
m p
of variability is : and M m :
On the basis of maxima observed in the years and listed in Table using
a least squares t we calculated the new preliminary elements
d
Max HJD : E
F AGERER
W MOSCHNER
Bundesdeutsche Arb eitsgemeinschaft
f urVer anderliche Sterne e V BAV
Munsterdamm
D Berlin Germany
E mail
agerer zweik t online de
wolfgang moschner t online de
References
Gessner H Ver o entlichungen der Sternwarte in Sonneberg
Ho meister C Astronomische Nachrichten
Kholop ov P N et al General Catalogue of Variable Stars th Edition Nauka
Moscow
Schwarzenberg Czerny A Monthly Notices R Astr Soc
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
THE NEW RR LYRAE STAR NSV IN ANDROMEDA
NSV Wr CSV was found to b e variable by Weber He p ointed
out that this ob ject could b e a Cepheid with a photographic magnitude variation from
m m
: to : The p osition given for this ob ject in the NSV catalogue Kholop ov is
erroneous Vidal Sainz et al In the original nding chart by Weber the susp ected
variable can b e unambiguously identi ed with GSC a star of photovisual
magnitude lo cated ab out one degree to the North of the p osition given by Kholop ov
In order to con rm the variability of NSV the star was observed for nights in
the V band from August to September As comparison stars GSC
was used and GSC GSC and GSC served as check stars
Observations were carried out from Monegrillo Observatory Spain using a CCD camera
and a m telescop e Figure
The gathered data showed that NSV is not a Cepheid but an RR Lyrae star
with a p erio d close to hours The phase curve Figure indicates that the amplitude of
m
the variation is : and the asymmetry factor M m P is The following
ephemeris has b een derived
d
Max HJD : E
Joaquin VIDAL SAINZ
Grup d Estudis Astronomics
Apartado
Barcelona
Spain
e mail vidal astro gea cesca es
References
Kholop ov P N editor New Catalogue of Susp ected Variable Stars Moscow
Vidal Sainz J Gomez Forrellad J M Garcia Melendo E IBVS No
Weber R IBVS No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
NSV A NEW ECLIPSING BINARY SYSTEM IN CANCER
Light variations of NSV CSV were initially observed by Rigollet
who rep orted that this ob ject was an RR Lyrae star According to his measurements
m m
NSV showed a photographic magnitude variation from : to :
From March to May NSV was observed for nights in the V band
from Monegrillo Observatory Spain A m telescop e and a Starlight Xpress CCD
camera were utilized Di erential photometry was p erformed using GSC as the
comparison star and GSC as check the star
Observational data show that NSV is not an RR Lyrae ob ject but an eclipsing
binary system with a p erio d over hours It can b e unambiguously identi ed with
GSC a star with a photovisual magnitude PAL V lter of The light
m m
curve shows b oth minima to b e partial with depths of : and : for the primary and
secondary minima resp ectively There is also detectable an O Connell e ect O Connell
m
that amounts to m Max I Max I I : Max I is at phase and
Max I I at phase
From the timing of seven minima see Table obtained according to the Kwee Van
Woerden metho d the following ephemeris was derived
d
Min I HJD : E
Table
HJD Minimum Ep o ch O C
II
II
I
II
I
I
I
The light curve suggests that NSV is a near contact binary system whose comp o
nents have very similar luminosity The light curve was preliminarily solved using Binary
Maker Bradstreet Although the O Connell e ect was mo deled as a dark sp ot
on one of the comp onents an initial solution was computed with no sp ots and then a
nal sp otted solution was obtained There was no information ab out sp ectral type for this reason it was not p ossible a priori to choose b etween a convective or radiative mo del
Nevertheless a b etter t was achieved with a convective mo del Additional photometric
and sp ectroscopic data should clarify this p oint The solution was then computed on a
convective mo del assuming a sp ectral type of F where a mean surface temp erature a con
vective mo del T K gravity darkening co e cients g g b olometric alb edos
A A and limb darkening co e cients x x were adopted
Elements of the b est solution are given in Table where and are the mo di ed
surface p otentials L and L are the normalized luminosities and a b c and d are
resp ectively the fractional back side p olar and p oint radii where the unit distance is
de ned as the distance b etween star centers
Once the unsp otted solution was reached it was re ned invoking a single sp ot No
further attempt was made to introduce more sp ots to improve light curve t It was
found that a dark area on the primary comp onent might b e resp onsible for the observed
O Connell e ect Sp ot radii b etween and yielded very similar solutions The in
termediate value of was nally chosen The rest of sp ot parameters sp ot s colatitude
and colongitude were xed to and resp ectively Table lists the sp ot parame
ters where T is the e ective temp erature co e cient Figure shows the light curve of
f
NSV sup erimp osed on the theoretical one
Table
mass ratio
i :
a a
g s
b b
g s
c c
g s
d d
g s
g g
T K T K K
L L
Figure
Table
Colatitude
Colongitude
Sp ot Radius
T
f
Sp ot is on primary star
Joaquin VIDAL SAINZ
Enrique GARCIA MELENDO
Grup d Estudis Astronomics
Esteve Duran Observatory
Apartado
El Montanya Seva
Barcelona
SEVA
Spain
Barcelona
e mail vidal astro gea cesca es
Spain
e mail duranobs astro gea cesca e
References
Bradstreet D H Binary Maker User Manual Contact Software Norristown
Pennsylvania
Kholop ov P N editor New Catalogue of Susp ected Variable Stars Moscow
Kwee K K van Woerden H BAN
O Connell D J K Pub Riverview Col l Obs
Rigollet R IAU Circ No
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
DISCOVERY OF AN SX Phe STAR IN NGC
NGC is a globular cluster of low concentration in which b oth Sara jedini
and Ferraro et al have lo cated many blue straggler BS candidates The present
pap er rep orts on the results of a search for variable blue stragglers in the central region
of the cluster carried out using B and V CCD frames obtained on four nights in
with the Las Campanas l m Swope telescop e One new variable was identi ed an
SX Phe star which is the ninth known variable in the cluster
The p osition of this star V as well as that of V an RR Lyrae star are shown in
Figure The numbers used to identify other stars in the gure are those from the pap er
by Sandage and Katem in which a chart of the entire cluster can b e found Both
variables fall just outside the region surveyed by Ferraro et al so no cross identi cation
can b e made with their observations X and Y co ordinates for V relative to the cluster
center as shown by Sandage and Katem and on the system of the Third Catalogue of
00 00
Variable Stars in Globular Clusters Sawyer Hogg are X Y
B and V magnitudes for b oth V and V determined using DAOPHOT Stetson
and calibrated with the photometry of Sara jedini are given in Tables and A p erio d
for V of day was found using a p erio dogram program
Figure Finding chart for V in NGC
Table B magnitudes for V and V
JD V V JD V V
Table V magnitudes for V and V
JD V V JD V V
V2
B 16.6
17.0
V 16.0
16.4
V9
B 19.0
19.4
V 18.6
19.0
0.5 1.0 0.5
Phase
Figure The B and V light curves for V and V in NGC constructed from the
CCD observations made on four nights in June
Light curves in B and V for b oth variables are shown in Figure The p erio d used for
V is that given by Wehlau The various symbols used in the plots represent
observations on each of the four nights The ep o chs of maximum were chosen from the
present data so that the folded light curves of V are plotted with the ephemeris
HJD of maximum E
and those for V with the ephemeris
HJD of maximum E
The authors acknowledge nancial supp ort from the Natural Sciences and Engineering
Research Council of Canada Thanks are also due to Tara Atcheson for plotting the light
curves
G G FAHLMAN
AMELIA WEHLAU
Dept of Physics and Astronomy
Dept of Physics and Astronomy
University of British Columbia
University of Western Ontario
Main Mall
London ON N A K Canada
Vancouver BC V T Z Canada
afwehlau phobos astro uwo ca
IAN THOMPSON
SLAVEK M RUCINSKI
Carnegie Observatories
JUN SHI
Santa Barbara St
York University
Pasadena CA
Keele Street
USA
North York ON M J K Canada
References
Ferraro F R Fusi Pecci F and Buonanno R MN
Sandage A and Katem B ApJ
Sara jedini A AJ
Sawyer Hogg H Publ DDO No
Stetson P B PASP
Wehlau A AJ
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
HBV V Her
The new variable star rep orted by Kohoutek was recorded indep endently during
the course of the UK Nova Patrol on hypered Ko dak TechPan lm exp osed on
August UT An approximate p osition was determined using the star AD Her
as reference on the True Visual Magnitude Photographic Star Atlas and a reasonably
con dent identi cation with the known variable V Her was recorded in the patrol
notes The ob ject app eared on the patrol lm to b e slightly defo cused and di use which
is typical of stars of Mira type the classi cation suggested by b oth the GCVS for V
Her and by Kohoutek for HBV The patrol notes also record a magnitude estimate
of which is certainly exaggerated by the red sensitivity of the TP emulsion Re
checking the lm the ob ject seen bright in August agrees exactly with the nder
given by Kohoutek although only the brighter stars in the eld are visible
The p osition given by Kohoutek for HBV agrees very well with the p osition of
h m s
IRAS at RA : Dec This seems to b e
the only bright IR source in the area listed in the IRAS Point Source Catalog It seems
likely therefore that there is only one Mira in this eld
V Her was originally found by Otto Morgenroth which was given the dis
h m s
covery designation AN Morgenroth gave a p osition RA Dec
0
: However Morgenroth s nder chart is in excellent agreement with
Kohoutek s nder con rming that HBV V Her but that the p osition given in
the GCVS presumably based on the p osition requires correction This would not
b e the rst time that a p ositional error has b een found in Morgenroth s work despite his
very reliable and sometimes very deep nders
Mike COLLINS
The Lawns
Everton
Bedfordshire
England SG LB
e mail compuserve com
References
Kohoutek L Inf Bul l Var Stars No
Morgenroth O Astron Nach
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC BVR OBSERVATIONS
C
OF THE NEW CEPHEID VARIABLE STAR GSC
Recently Antipin has analysed photographic archival plates at Sternberg Astro
nomical Institute of Moscow and found that the star GSC is a Cepheid variable
with the elements
Max JD E
hel
We observed this Cepheid photo electrically at Mt Maidanak observatory in August
using the cm re ector a total of BVR measurements were obtained Table
c
m m
the accuracy of the individual data is near in V and near in B V and
V R Ab ove elements are used in Figure for plotting our observations According
c
m m m
to our data the amplitude of the light curve is in V in B V and in
V R
c
The research describ ed here was made p ossible in part by grants No and
No from the Russian Foundation of Basic Research
Table
JD V B V V R JD V B V V R
hel c hel c
V GSC4019.3103 P=5.350 11.0 11.3 B-V 1.2 1.4 V-R C 0.8 1.0
0.0 0.5 1.0 Phase
Figure The light curve
L N BERDNIKOV
O V VOZYAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
V V IGNATOVA
Astronomical Institute
Astronomicheskaya ul
Tashkent Uzb ekistan
Reference
Antipin S V Peremennye Zvezdy in press
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC BVR OBSERVATIONS
C
FOR THE NEW CEPHEID VARIABLE STAR GSC
Recently Antipin has analysed photographic archival plates at Sternberg Astro
nomical Institute of Moscow and found that the star GSC is a Cepheid variable
with the elements
Max JD E
hel
We observed this Cepheid photo electrically at Mt Maidanak observatory in August
using the cm re ector a total of BVR measurements were obtained Table
c
m m
the accuracy of the individual data is near in V and near in B V and
V R Ab ove elements are used in Figure for plotting our observations According
c
m m m
to our data the amplitude of the light curve is in V in B V and in
V R
c
The research describ ed here was made p ossible in part by grants No and
No from the Russian Foundation of Basic Research
Table
JD V B V V R JD V B V V R
hel c hel c
V GSC3596.0433 P=2.418 11.8
12.3 B-V 1.5 1.7 V-R C 0.9 1.1
0.0 0.5 1.0 Phase
Figure
L N BERDNIKOV
O V VOZYAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
V V IGNATOVA
Astronomical Institute
Astronomicheskaya ul
Tashkent Uzb ekistan
Reference
Antipin S V Peremennye Zvezdy in press
COMMISSIONS AND OF THE IAU
INFORMATION BULLETIN ON VARIABLE STARS
Number
Konkoly Observatory
Budap est
November
HU ISSN
PHOTOELECTRIC BVR OBSERVATIONS OF THE CEPHEID V Cas
c
Recently Shugarov has analysed photographic archival plates at Sternberg As
tronomical Institute of Moscow and found that V Cas is a Cepheid variable with the
elements
Max JD E
hel
We observed this Cepheid photo electrically at Mt Maidanak observatory in August
using the cm re ector a total of BVR measurements were obtained Table
c
m m
the accuracy of the individual data is near in V and near in B V and
V R Ab ove elements are used in Figure for plotting our observations According
c
m m m
to our data the amplitude of the light curve is in V in B V and in
V R
c
The research describ ed here was made p ossible in part by grants No and
No from the Russian Foundation of Basic Research
Table
JD V B V V R JD V B V V R
hel c hel c
V V553 Cas P=4.900 13.0
13.7 B-V 1.6 1.9 V-R C 1.0 1.2
0.0 0.5 1.0 Phase
Figure
L N BERDNIKOV
O V VOZYAKOVA
Sternberg Astronomical Institute
Universitetskij prosp
Moscow Russia
V V IGNATOVA
Astronomical Institute
Astronomicheskaya ul
Tashkent Uzb ekistan
Reference
Shugarov S Yu private communication
COMMISSIONS AND OF THE IAU
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Number
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November
HU ISSN
PHOTOELECTRIC MINIMA OF FOUR RS CVn TYPE
BINARY SYSTEMS RT And SV Cam WY Cnc AND Z Her
We present moments of minima observations of four RS CVn type binary systems
made with cm Maksutov telescop e for RT And WY Cnc and Z Her and with the
cm Cassegrain telescop e for SV Cam of the Ankara University Observatory Both tele
scop es are equipp ed with an SSP A photometer containing a side on R Hamamatsu
photomultiplier but R Hamamatsu photomultiplier for the Cassegrain telescop e In
dividual measurements for RT And and WY Cnc and Z Her were obtained in B and V
lters for SV Cam were obtained in B and V and R lters The reduction of the photo
electric data was made by standard pro cedures for di erential extinction and light time
e ect The comparison stars used in observations of the four systems are listed in Table
All minimum times were computed using the metho d of Kwee and van Woerden
The results are listed in Table with their mean errors
We would like to thank to Dr Z M uyessero glufor his help
Table The comparison stars used
Variable Comparison
RT And BD
SV Cam BD
WY Cnc BD
Z Her BD
1
BERAHITDIN ALBAYRAK
2
FERHAT FIKRI OZEREN
3
FEHMI EKMEK C I
Ankara University Observatory
Tando gan Ankara Turkey
E mails
1
albayrak dione astro science ankara edu tr
2
ozeren dione astro science ankara edu tr
3
ekmekci dione astro science ankara edu tr
Reference
Kwee K K and van Woerden H Bul l Astron Inst Neth
Table Brightness minima of RT And SV Cam WY Cnc and Z Her
Star Min Min HJD Mean Filter
Type err
RT And I B
I V
II B
II V
SV Cam I B
I V
I R
I B
I V
I R
II B
II V
II R
II B
II V
II R
WY Cnc I B
I V
Z Her I B
I V COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 4400
Konkoly Observatory Budapest 25 November 1996 HU ISSN 0374 – 0676
PHOTOMETRY OF THE ACTIVE-CHROMOSPHERE ECLIPSING BINARY, HD 9770
The visual triple system HD 9770 comprises two K dwarf stars (A and B) in a well- determined 4.559-year orbit, together with a third star (C), an M dwarf, with an orbital period of 111.8 years. The semi-major axes are 0′′.171 forAB and 1′′.419 for AB-C (Hirshfeld & Sinnott, 1985). The parallax is given as 0′′.052 ± 0′′.007 by Jenkins (1963). The spectral types according to Edwards (1976) are K3V (A), K4V (B) and M2V (C). The M dwarf is more than 4 magnitudes fainter in V than the combined light from AB. According to the compilation of Hirshfeld and Sinnott (1985) the visual magnitudes of the three stars are 7.8, 7.9 and 11.5 for A, B and C respectively, although the angular proximity of the objects in the sky must make these figures approximate only. The system ABC contains at least one active chromosphere star, as shown by EUV emission from both the ROSAT (Pounds et al., 1993; Pye et al., 1995) and EUVE all-sky surveys (Malina et al., 1994; Bowyer et al. 1994). The definitive identification of the ROSAT WFC source 2RE013501–295430 with the star HD9770 (Gliese 60 A,B,C) was made by Mason et al. (1995), based in part on 1-A˚ resolution spectra recorded in 1991–92 on the SAAO 1.9-m telescope at the H and K lines, which show some H and K emission (approximate equivalent width of emission 0.2 A).˚ The emission may be variable both in strength and radial velocity. On the other hand the Michigan Spectral Catalogue (Houk, 1982) gives a spectral type of K1 V and there is no mention of H and K emission — presumably because of lower resolution. The galactic (U, V, W ) velocity components for HD 9770 calculated by Eggen (1962) are (+22.2, −5.3, −31.6) km/s. Such velocity components are typical of old disk stars, so we do not infer any chromospheric emission arising from extreme youth. HD 9770 appears in a list of suspected variable stars by Petit (1980), but neither the magnitude range nor the type of variability are specified. Cutispoto et al. (1995) subsequently found an amplitude in V of about 0.07 mag. and a period of 6.29 ± 0.24 days. Photoelectric photometry has been carried out in the UBV (RI)C system since 1992 Nov. 3 on the SAAO 0.5-m telescope at Sutherland, S.A. and on the two 0.61-m tele- scopes at MJUO, Tekapo, N.Z. The comparison and check stars selected were respectively HD9349 and HD9576. Our observations have confirmed that the system is indeed variable, with an amplitude from maximum to minimum of about 0.25 mag. in V . We have found that one of the visual binary components is itself an eclipsing binary for which the ephemeris of primary eclipse is
HJD = 2448930.6448+ 0.476525 × E 2
Figure 1. Phased V light curve from SAAO and MJUO photometry of HD 9770
Our phased light curve (Figure 1) shows that the primary eclipse has a depth of about 0m. 22, whereas the secondary eclipse is about 0m. 20. We therefore prefer the above ephemeris to one in which the period is only half as long and the secondary eclipse is not visible. The orbit appears to be close to circular, as the phase of central secondary eclipse is 0.50 and the eclipses are of comparable duration. We therefore deduce that the two stars in the eclipsing binary system are of very similar spectral type, presumably both K dwarfs. Hence the visual binary system AB must contain three K dwarfs all of compa- rable mass. If the stars were of equal magnitude and the third star not participating in the eclipses were absent, then the primary eclipse depth would be 0m. 35 instead of 0m. 22, suggesting that the eclipses are not total. In addition to the variability due to the eclipses, there is considerable scatter over the four years of our observations in the out-of-eclipse magnitudes. The combined magnitude of the system ABC was as bright as 7.10 in 1992, but about 7.14 in 1994. Such variations are typical in active-chromosphere binary stars, because of the variation in spot numbers on timescales of years. Some of the scatter may also arise because of the drift in orbital phase of the rotationally modulated spot wave. Much of our data came from 1994 observations at MJUO. The scatter for this year is clearly less than for all the photometric data considered together (see Figure 1). We find no evidence for the 6.29-day variation reported by Cutispoto et al. (1995). It is noted that the orbital period of 11h26m. 2 found for the eclipsing binary system is the shortest of any active-chromosphere binary listed in the catalogue of Strassmeier et al. (1993), although several have periods of about half a day. Although the AB visual binary has a well-determined orbit, the uncertain parallax renders a mass with quite large error bars. It is +0.93 MA + MB =1.71−0.54M⊙ 3 ′′ The higher mass limit is 2.64M⊙, corresponding to a parallax of about 0.045. Since we anticipate that the AB system in practice contains three K dwarfs of spectral type about K3 V or K4 V, whose masses should therefore each be about 0.75M⊙, a total mass of about 2.25M⊙ might be expected for the AB system. This total mass is entirely consistent with the AB orbit and the parallax, given the rather large parallax uncertainty. The Hipparcos parallax will soon constrain the total mass of this system to a much narrower range. The orbit of the AB-C system is not well enough determined to add much useful information to the total mass. A programme of high dispersion ´echelle spectroscopy using the 1-m McLellan telescope at MJUO has been undertaken on HD 9770 since 1993 March. Most of the data are at Hα, which shows a fairly normal K dwarf profile without obvious Balmer emission, but the central depth is only 0.45, consistent with the presence of the two other stars which may have some chromospheric emission (Figure 2). Radial velocities have been measured from the Hα and metallic lines, and the results will be reported in a subsequent paper (Watson et al., 1997). The velocities show only small variations around +32.5 km/s, showing that the sharp-lined spectrum being measured is from the third K star which is not part of the eclipsing binary system. IUE spectra were also recorded in 1996 August, from both the long wavelength camera at high dispersion and the short wavelength camera at low dispersion. These spectra show chromospheric emission lines consistent with the EUV emission and the chromospheric emission at H and K. They will also be discussed in our subsequent publication.
Figure 2. Typical MJUO Hα ´echelle spectrum of HD 9770 4 We note that the two eclipsing K stars are expected to show a radial-velocity amplitude of about 340 km/s and, assuming they are tidally locked, rotational line broadening in each star of about 80 km/s. Such broad diffuse lines may be present in our ´echelle spectra, but we need to study the spectra further to be certain of this. Figure 2 shows the dominant sharp lines, which are clearly those of the third K dwarf outside the eclipsing binary.
G.E. BROMAGE1, D.A.H. BUCKLEY2 A.C. GILMORE3 J.B. HEARNSHAW3 P.M. KILMARTIN3 L.C. WATSON3 1 Centre for Astrophysics, Univ. Central Lancashire, Preston, Lancs. PR1 2HE, U.K. 2 South African Astronomical Observatory4, Observatory 7935, Cape Town, S.A. 3 Mt John University Observatory5, Depart. of Physics and Astronomy, Univ. of Canterbury, Christchurch, N.Z.
References: Bowyer et al. 1994, Astrophys. J. Suppl., 93, 569 Cutispoto, G. Pallavicini, R. K¨urster, M., Rodon`o, M., 1995, Astron. & Astrophys., 297, 764 Edwards, T.W., 1976, Astron. J., 81, 245 Eggen, O.J., 1962, Roy. Observ. Bull., No. 51 Hirshfeld, A. and Sinnott, R.W. 1985, Sky Catalogue 2000, vol. 2, Sky Publ. Corp. & Cambridge Univ. Press Houk, N. 1982, Michigan Spectral Catalogue, vol. 3, Univ. Michigan, Ann Arbor Jenkins, L.F., 1963, Suppl. to the General Catalogue of Trigonometric Stellar Parallaxes, Yale Univ. Observ., Conn. Malina, R.F. et al., 1994, Astron. J., 107, 751 Mason, K.O. et al., 1995, Mon. Not. R. Astron. Soc., 274, 1194 Petit, M., 1980, Inf. Bull. Var. Stars, No.1788 Pounds, K.A. et al., 1993, Mon. Not. R. Astron. Soc., 260, 77 Pye, J.P. et al., 1995, Mon. Not. R. Astron. Soc., 274, 1165 Strassmeier, K.G., Hall, D.S., Fekel, F.C. and Scheck, M., 1993, Astron. & Astrophys. Suppl., 100, 73 Watson, L.C. et al., 1997, in preparation
4SAAO 5MJUO