This dissertation has been microfilmed exactly as received 68-3028
MEISEL, David Dering, 1940- A STUDY OF MULTIPLE STAR SYSTEMS INVOLVING COMPONENTS OF SPECIAL A ST RO PHY SICA L INTEREST.
The Ohio State University, Ph.D., 1967 Astronomy
University Microfilms, Inc., Ann Arbor, Michigan A STUDY OF MULTIPLE STAR SYSTEMS INVOLVING. COMPONENTS
OF SPECIAL ASTROPHYSICAL INTEREST
DISSERTATION
Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University
By
David. Dering Meisel, B.S., M.S.
The Ohio State University 1967
Approved by
Adviser Department of Astronomy ACKNOWLEDGMENTS
I would like to thank Dr. Arne Slettebak, Dr. George Collins, and
Dr. Phillip Keenan of the Perkins Observatory Staff for their suggestions, comments and patience during all phases of this work. Also I would like to thank Dr. Walter Mitchell for the loan of the Gerber GOAT in order to complete the microphotometer reduction. Also I would thank Dr. Carlos and
Mercedes Jaschek for reading the manuscript, particularly the notes to
Table 6, and for their valuable comments.
The help of a number of other people and institutions is also grate fully acknowledged; in particular, Father F. J. Heyden at Georgetown
College Observatory for time on their microphotometer, Ted Fay and Dr.
Holis Johnson for the radial velocity reduction program and three runs on the Indiana University CDC computer, and the staff of the University of Virginia Computer Science Center for generous support.
I would, like to thank my colleagues at the Leander McCormick Obser vatory for suggestions and their aid of telescope time and equipment with out which the photometry could not have been completed.
I am grateful to Dr. Collins of the Perkins Observatory and Dr. H.
John Wood of the McCormick staff for providing results especially for this work and in advance of their own publications.
Travel and telescope time on the Perkins telescope and equipment at
Flagstaff and Columbus provided by the Ohio State and Ohio Wesleyan Uni versities is gratefully acknowledged. VITA
March 28, 19^0 Born - Fairmont, West Virginia
1961 B.S., West Virginia University, Morgantown, West Virginia
1962-1963 Teaching Assistant, Department of Astronomy The Ohio State University, Columbus, Ohio
I963 M.S., The Ohio State University, Columbus, Ohio
1963-1965 Perkins Observatory Assistant, Department of Astronomy, The Ohio State University, Columbus, Ohio
1965-1967 Instructor, Department of Astronomy University of Virginia, Charlottesville, Virginia
FIELDS OF STUDY
Major Field: Astronomy
Studies in Physics. Professors 0. Rex Ford and Charles N. Thomas
Studies in Cometary Astronomy. Professor Nicholas T. Bobrovnikoff
Studies in Astrophysics. Professor Arne Slettebak
iii TABLE OF CONTENTS
page
ACKNOWLEDGEMENTS ...... ii
VITA ...... ■...... iii
TABLE OF C O N T E N T S ...... iv
LIST OF TABL E S...... v
LIST OF ILLUSTRATIONS...... vi
Chapter I. INTRODUCTION ...... 1
Chapter II. THE OBSERVATIONS ...... 13
Chapter III. THE RESULTS AND DI S C U S S I O N ...... 6l
Chapter IV. SUMMARY AND CONCLUSIONS ...... 84
BIBLIOGRAPHY...... 8 7
iv LIST OF TABLES
Table page
1. List of S t a r s ...... 5
2. Index Catalogue ...... 8
3. V Sin i, Spectral Classification Standards . 19
Photoelectric D a t a ...... 29
5. Indices and Equivalent W i d t h s ...... 33
6. Spectral Types and Rotational Velocities ...... 37
7. H-gamma Values for C o m p a n i o n s ...... 56
8. Absolute Magnitude Calibration ...... 62
9. Absolute Mlagnitudes from Hydrogen Li n e s ...... 68
10. Mean Deviations of Calibrated AbsoluteMagnitudes .... 71
11. Mean Rotational Velocities ...... 75
12. Statistical Correlation Data ...... 79
v LIST OF ILLUSTRATIONS
, Figure page
1. Correlations Between Spectral Types ...... 22
2. Correlation Between Luminosity Classes ...... 23
3. Magnitude Difference Residuals ...... 23
4. Correlations of Rotational Velocities ...... 24
5. Correlation Between Magnitude Differences ...... 25
6. Correlation Between Equivalent Widths ...... 26
7. H-R Diagram for Early-type Stars ...... 66
8. H-R Diagram for Late-type S t a r s ...... 67
9. Correlation Between Absolute Magnitudes ...... 73
10. Rotational Velocity Means for Class V ...... 76
11. Rotational Velocity Means for Classes IV, III ...... 76
12. Rotational Velocity Means for Be S t a r s ...... 76
Chart
1. S Monocerotis System ...... 12
2. HD 15238-9 S y s t e m ...... 12
3. HD 190918 12
vi CHAPTER I
INTRODUCTION
Wide visual multiple stars, unlike close binaries, afford an opportunity to examine, in detail, the astrophysical properties of two or more stars which presumably were formed in the same neighborhood of space and under similar conditions of composition, density, and mean angular momentum, but have evolved independently. Since the formation of physical systems by close encounters between stars of widely different ages is very improbable, the assumption is usually made that the compo nents of all systems showing common dynamical properties, have similar ages. Thus visual multiple star systems might be used to study stellar evolution and rotation with techniques similar to those that have been successful with star clusters. In the study of visual binary systems, however, the apparent proximity of the components and the possibility of mere optical connection present difficulty in both observation and inter pretation. In the closer visual binaries, the existence of an orbit is sufficient to establish dynamical connection, but the observational diffi culties are more severe. For wide pairs, the observational problems are not as great, but the establishment of dynamical connection becomes more difficult.
In spite of the observational and dynamical difficulties, astrophy sical investigations of visual double and multiple stars have been carried out by Leonard (1923), Johnson (1953), Wallenquist (195^,1958), Struve and
Franklin (1955), Struve, Franklin, and Stableford (1955), Opolsky (1956), 2 Bakos and Oke (1957). Bidelman (1958), Bakos (1959), Hopmann (1959),
Stephenson (I960), Wallerstein and Westfall (i960), Berger (1962), Slette- bak (1963), Cester (1963), Eggen (1963, 1965), Tolbert (1964), Petrie and
Batten (1966) and others.
In the study described here, the visual double stars involving 0 and
B-type stars, supergiants, and Be stars constituted the primary groups of interest. In addition, pairs having other characteristics of interest were included for the observing program. A master list of some 1200 pairs was compiled by cross-referencing the Index Catalogue of Double Stars 1961.0
(ICDS) (H. M. Jeffers, W. H. van den Bos, and F. M. Greeby, 1963) with the special lists given below. (It is hoped to publish a revised and extended version of the master list at a later date. No attempt was made to differentiate between optical and physical pairs.)
OB stars - Morgan, Code, and Whitford (1955)•
Supergiants - Johnson and Morgan (1953); Wilson (19^1); Bidelman
(1957a, 1957b).
Be stars - Merrill and Burwell (1933, 19^3, 19^9).
Bp and Ap stars - Bertaud (1959, I960).
WR and Ce stars - Roberts (1962); Stephenson (1965).
Variable stars - Kukarkin, Paranago, et. al. (1958-1964); Plaut
(193^, 1939); Hertzsprung (1922); Baize (1962);
Perova (1964).
Eclipsing binaries - Koch, Sobieski and Wood (1963); Tchudovitchov
(1951).
Spectroscopic binaries - Moore (1936); Moore and Neubauer (1948);
Koritnikov, Laurov, and Martinov (196I-I963).
High velocity stars - Roman (1955)•
Composite spectra - Hynek (1938). 3 The systems given initial consideration were selected by taking observational difficulties such as limiting magnitude, separation, orien tation, and declination into account. During the actual observing periods,
OB stars, supergiants, and Be stars were given the highest priority while stars having composite spectra were considered to have the lowest priority.
A total of 66 systems was studied. Using interstellar line intensities,
H-gamma equivalent widths, radial velocities, and proper motions (where available), sixteen of these were considered to be optical and were re jected for further study.
The main purposes of the present study are:
1) calibration of the absolute magnitudes of specific components,
especially those exhibiting interesting or peculiar astrophysical
characteristics;
2) investigation of the axial rotation characteristics of the visual
components;
3) empirical investigation of the effects of rotation on the cali
brated luminosities, Balmer-line measurements, and spectral types
for the sample of stars available.
The astrophysical data obtained from moderate dispersion spectra and photoelectric photometry were:
1) spectral types and luminosity classes on the M system;
2) rotational velocities (V sin i) using both eye-estimates and
line half-intensity-widths;
3) photoelectric ^mv values for a number of pairs;
4) H-gamma equivalent widths determined photoelectrically and from
photographic microphotometry;
5) H-beta indices. Table 1 lists the stars considered to be physically connected with 14 one or more components for which data were obtained in this study, followed by a list of the stars which have optical components only. The table gives the 1900.0 coordinates, ADS number and HD number, star name (if used instead of HD number), and the characteristic for which the pair was selected for study. Table 2 lists available double star data from the ICDS for all components of the systems studied. Finder charts for three systems where the notation used here differs from that in Table 2 are provided. The
ICDS notation is enclosed in parentheses on these charts. TABLE 1 - LIST OF STABS OF PARTICULAR INTEREST
Number R.A.(1900) Deo.(1900) ADS HD/ Name Characteristic0
A. STARS WITH PHYSICAL COMPONENTS
1 00 30.7 29 27 497 3266 HV 2 00 34.8 55 59 561 3712 aCas Var 3 00 47.0 56 05 719 5005 OB 4 01 26.6 60 10 1209 9311 OB,SG 5 02 2008 66 57 I860 15089 t Cas Var 6 02 22.2 60 13 18 77 15239 Be 7 02 43.4 55 29 2157 17506 nPer SG 8 02 53.1 59 16 - 18473 Bp 9 03 4o.l 41 10 2757 23439 HV 10 03 41.9 52 21 2783 23675 OB 11 03 52.5 47 52 - 24909 IQ Per EB 12a 05 32.7 00 55 — 37330 Be 13 05 17.6 03 27 3962 35149 23 Ori 0B 14 06 23.0 20 17 5103 45542 vGem Be 15 06 24.0 -06 58 5107 45725 3Mon Be 16 06 25.6 11 19 5153 45995 OB 17 06 26.0 04 54 — 46056 OB 18/19 06 35.5 10 00 5322 47839 S Mon Var, OB 20 06 46.1 -31 36 — 50123 Be 21 11 59.2 22 01 840 6 104827 2 Com FOp 22 13 47.5 -31 26 - 120955 h Cen SB 23 15 32.4 64 14 9706 139319 TW Dra SB, EB 24 16 30.9 17 15 — 149632 SB 25 17 29.9 06 06 10638 159481 HV 26 18 07.8 -21 05 IH 69 166937 pSgr SG,SB,EB 27 18 22.1 00 08 11353 169986 d Ser SB, Var 28 19 01.9 57 19 12019 178001 EB TABLE 1 - Continued 29 19 09.5 49 40 12169 179957-8 HV 30 19 28.9 20 12 12594 184360 HV 31 19 45.5 17 42 - I87566 Ap 32 19 56.7 10 28 13256 I89783 SB 33 20 01.9 35 19 13361 190864 OB 34 20 02.2 35 31 13374 190918 OB, SG 35 20 02.3 35 29 13376 227634 OB, SG 36 20 05.5 35 11 13429 191566-7 OB 37 20 12.1 -12 49 13632 192876 01 Cap SG 38 20 12.8 37 20 13626 193007 OB, SG 39 20 14.6 40 25 13672 193322 OB 40 20 15.4 -15 06 - 193495 8 Cap SB 41 20 56.4 47 08 14526 200120 59 cyg Be 42 21 04.4 29 48 14682 201433 V389 Cyg SB 21 16.7 61 25 14868 203374 Be Z^b 21 31.5 -19 54 - 205637 eCap Be 45 21 35.9 57 02 15184 206267 OB 46 22 04.9 59 14 (59°2485) 210940 LG 47 22 34.8 38 32 16148 214680 10 Lac OB 48 22 37.0 39 43 - 214993 12 Lac Var, OB 49 22 42.7 -04 45 16270 215812 HV 50 23 25.4 58 00 16795 221253 AR Cas EB, OB B. Pairs Considered Optical for All Components Studied
0-1 00 17.4 61 41 307 1810 OB 0-2 02 33.1 60 51 2018 16429 OB 0-3 04 10.1 45 58 — 26906 Be 0-4 06 37.5 01 49 5364 48279 OB 0-5 06 56.4 -02 54 5705 52504 OB 0-6 06 58.2 20 43 5742 52973 5 Gem Var 0-7 07 20.1 -29 06 - 58350 nC Ma SG 0-8 16 15.1 -25 21 10009 147165 0 Sco Var 0-9 ' 18 49.7 59 15 11779 175306 0 Dra SB 0-10 20 01.5 -09 12 13380C 190724C RY Cap Var 0-11 20 10.8 36 30 - 192640 29 Cyg Ap cn TABLE 1 - Continued. 0-12 20 16.5 47 35 — 193680 U Cyg Var 0-13 20 43.5 36 01 14296 198183 X Cyg Be 0-14 21 21.7 36 14 14969 204172 69 Cyg SG 0-15 22 2 6.5 56 43 16001 213470 SG 0-16 22 51.8 41 04 1638I 216916 EN Lac Var
Notes to Table 1. a Pair is considered, physical, although A m is more consistent for normal stars of the same spectral type. b Pair is considered physical although the MK luminosity criteria for the companion disagree. c Particular feature for which star was chosen in this study. The abbreviations used are: HV - high velocity star BE - B type emission star OB - early type star Var - light variable p - peculiar star EB - eclipsing binary SG - supergiant SB - spectroscopic binary LG - late type giant TABLE 2 - INDEX CATALOGUE LISTINGS FOR SYSTEMS STUDIED
Approximate Separations ADS HD/Name Magnitude (ICDS) (seconds of arc)
307 . 1810 AB 8.4 — 10.4 10 AC 8.3 10.8 25 AD 8.4 — 9.9 47 497 3266 AB 9.0 - 9.8 6 AC 8.7 11.4 127 561 a Cas AB 2.5 — 14.0 20 AC 2.5 - 13.0 38 AD 2.5 - 8.5 64 710 5005 AB 7.9 - 9.9 1 AC 8.1 - 8.9 4 AD 8.0 — 9.4 10 AE 7.7 12.1 16 1209 9311 AB 7.4- - 10.6 14 AC 7.3 10.9 28 AD 7.4 - ? 56 AE 7.3 — ? 83 I860 15089 AB 4.7 — 7.6 ORBIT AC 4-. 6 8.5 6 1877a 15238 AB 8.3 — 11.5 18 STF264 AA' 8.2 — 8.4 139 STF264 A'B* 8.8 — 9.8 16 2018 16429 AB 8.0 — 10.0 6.( AC 7.8 — ? 53 2157 17506 AB 3.9 — 7.9 28 ( nPer)AC 3.9 - 9.9 67 CD 9-9 - 10.4 5 AE 9.2 - 10.6 238 ------18473 AB 7.4' — 8.8 74 27 57 23479 AB 8.7 - 9.3 8 AC 8.3 - 11.1 14 CD 11.1 — 13.8 4 2783 23675 AB 6.9 — 9-1 9 AC 6.8 — 12.0 12 AD 6.8 — 10.3 67 DE 10.3 — 10.7 3 ------IQ Per AB 8.1 - 9.4 39 BC 9.4 - 15.0 32 ------26906-7AB 7.2 8.6 58 3962 23 Ori AB 5.0 - 7.1 32 ------37330 AB 7.2 - 7.9 80 5103 v Gem AA 4.1 — ? 0.; AB 4.1 - 8.6 13 AP 4.1 - 15.1 24 AQ 4.1 - 13.9 54 AR 4.1 - 12.6 57 BC 8.6 — 8.9 0.; 5107 6 Mon AB 4.7 - 5.2 7 AC 5.1 - 6.1 10 TABLE 2 - Continued
Approximate Separations ADS HD/Name Magnitudes (seconds of arc)
AD 4.7 _ 12.2 26 5153 45995 AB 5.9 — 8.1 16 --- 46056 AB 8.3 - 9.7 10 5325° AB 10.7 - 10.8 4 (D 11) AC 10.7 — 10.8 41 5322b S Mon AB 4.8 _ 7.6 3 AC 4.7 - 9.9 16 AD 4.7 - 9.7 41 AE 4.7 — 10.0 74 AF 4.8 — 7.8 156 AK 4.7 — 8.2 106 AS 4.7 - 9.7 137 FS 7.8 - 9.8 98 GS 8.3 — 9.8 98 SMon&DllCc 4.8 — 8.0 90 SMon&STF952 4.8 - 9.4 78 STF952 AB 10.2 - 10.2 14 AC 10.2 — 10.2 133 5364 48279 AB 7.9 - 10.9 6 AC 8.3 - 9.0 36 AD 7.9 - 10.9 56 50123 AB 5.6 - 8.2 43 BC 8.3 — 10.6 0.6 5705 52504 AB 7.9 - 15.1 3 AC 8.3 - 9.2 9 5742 52972 AB Var. - 10.5 ' 87 AC 3.0 - 8.0 96 AP - 12.0 80 CH 8.6 - 12.9 27 ------58350 AB 2.4 - 6.9 179 840 6 2 Com AB 6.0 — 7.5 4 ------h Cen AB 4.8 — 8.5 15 9706 TW Dra AB Var. - 9-5 3 10009 a Sco AB 3.1 — 8.7 21 ------149631-:2AB 6.3 — 7.3 156 10638 159481 AB 8.0 — ll.o 28 AC 7.9 - 8.5 80 AD 8.4 - 9.1 90 AE 7.9 - 11.4 145 11169 v Sgr AB 4.0 — 11.5 17 AC 4.0 - 13.5 26 AD 4.0 — 9.9 48 AE 4.0 - 9.4 50 11353 d Ser AB 5.4 — 7.7 4 AP 5.3 — ? 0.1 11779 0 Dra AB 4.9 - 7.9 34 AC 4.9 - 11.5 140 1° TABLE 2 - Continued
Approximate Separations ADS HD/Name Magnitudes (seconds of arc)
12019 I78OOI AB 8.4 — 8.9 11 12169 179957-8 AB 6.6 - 6.8 8 AC 6.6 — 13.3 47 AD 6.6 — 11.4 173 12594 184360 AB 7.4 — 8.9 5 AC 7.2 - 12.5 147 AP 7.2 _ ? 0.4 ------I87566 AB 8.3 — 10.3 25 AC 8.1 - 9.3 69 13256 I89783 AB 7.6 7.8 4 13380 Near 190774 AB 7.8 - 10.5 6 AC 7.7 — 12.6 8 13361 190864 AB 8.7 — 9.2 70 BP 9.2 - 14.2 10 BQ 9.2 _ 13.2 17 13374b I909I8 AB 7.0 12.0 7 AC 7.0 — 11.0 10 AD 7.1 - 9.6 11 AE 7.0 — 11.5 28 AP 7.0 - 8.0 36 — T-\ AH 7.0 13.8 30 13376° 227634AB 8.2 — 12.0 8 AC 8.2 14.8 11 AD 8.4 — 8.8 20 13429 191566-67AB 7.6 _ 8.6 6 SEI923 9.7 - 10.1 28 ------29 Cyg AB 5.0 - 6.6 12 AC 5.0 — 10.0 22 AP 5.0 « 12.2 37 13632 a Cap AB 4.6 — 14.1 44 AC 4.6 - 9.6 45 DC 14.3 — 9.6 29 13626 193007 AB 8.5 — 9.0 19 AP 8.1 - 10.8 4 AQ 8.0 — ? 9 AR 8.0 — 9.6 19 BC 8.0 - 9.6 17 BS 9.0 - 14.5 4 BT 9.0 - 11.5 7 CN 9.6 - 13.0 12 CV 9.7 — 12.8 21 CW 9.6 - 13.7 15 AP* 8.0 - 10.9 26 AQ' 8.1 — 11.1 20 AH’ 8.5 — 11.9 8 13672 193322 AB 5.9 — 8.1 3 AC 5.9 - 8.6 34 AD 5.9 - 9.2 11 TABLE 2 - Continued
Approximate Separations ADS______HD/Name Magnitudes (seconds of arc)
— — — _ 3 Cap AB 3.^ — 6.2 20 5 AC 3-^ - 9.0 226 U Cyg AB Var. — 7.8 64- 14-296 * Cyg AB 4-. 8 - 6.1 ORBIT (AB-C) 4-.8 - 9.9 85 14-526 59 Cyg AB 4.9 - 9.8 20 AC 4-.9 - 11.7 27 AD 4-.9 - 11.2 38 14-682 V389 Cyg AB 5.8 - 7-8 3 AC 5.7 - 8.9 58 AD 5.6 - ? 74- 14-868 203374- AB 6.6 - 10.0 ^5 BC 10.1 - 12.7 3 14-969 69 Cyg AB 5.8 - 10.2 33 AC 5.9 - 8.9 54------e Cap AB 4-.7 - 9.5 68 15184- 206267 AB 5.6 - 13.3 2 AC 5.8 - 7.7 12 AD 5.8 - 7.8 20 CD 7.7 - 7.8 30 PLE 7.9 - 11 53 +59°24-85d AB 8.8 - 9.3 65 1614-8 10 Lac AB 4-.9 - 8.4- 62 — - —- 12 Lac AB 5.2 - 9.2 69 16270 215812/3 AB 7.3 - 7.8 3 AC 7.1 - 8.3 50 AD 6.8 - ? 1 I638I EN Lac AB 5.5 — 11.5 28 AC 5.6 — 8.6 63 I6795 AR Cas AB 4-.9 - 9.3 2 AC 4-.9 - 7.1 76 AE ^.9 - 8.9 ^3 AP 4-.9 - 8.9 67 AG 4-.9 - 9.1 67 CD 7.1 - 12.9 27 CH 8.9 - 9.1 11
Notes to Table 2 a Proper motion pairs. Other components present. Components listed do not correspond to actual system. See identi fication chart for notation used in this study, b Do not correspond to actual components. See identification chart for notation used in this study, c Magnitude wrong in ICDS. d Not in ICDS. 12
CHART 1 - S Monocerotis System Index Catalogue Notation Shown in Parentheses
©(F)
FI •(S) F2 • C (G) 0 (STF952) (B) © PA E(E) •a «C) (D)®
NORTH ©ADS 5325 I I HO" arc
CHART 2 - HD 15238-9 System CHART 3 - HD 190918-9 System Index Catalogue Notation Index Catalogue Notation Shown in Parentheses Shown in Parentheses
HD 19086H i. ®AW)
D B (B) HD 190919 I HD 15239 B (B) A(A)
B(D) © • C(C) ° D(B)
NORTH HD 22763H
1 20" arc SfcA(A') F HD 15238 HD 190918 Q ). t *E(B) NORTH C(D) ® 10(C) a *G(E) L B(F) w 30" arc
BBSk GSBRMBUMt CHAPTER II
THE OBSERVATIONS
The spectrograms used in this study were taken with the 72-inch
Perkins telescope of the Ohio State and Ohio Wesleyan Universities at the
Lowell Observatory. The 8-inch camera of the Yoder spectrograph was used to obtain plates having a dispersion of 42 S/mm at H-gamma, a range of
3400 to 5000 S was covered on Kodak IIa-0 emulsions baked 72 hours at
51°C. MK standard star spectrograms with 0.5 mm spectrum widths, previously taken by Slettebak, were supplemented with additional spectrograms for spectral types later than F8, where necessary. The spectra of the program stars were taken at the same width when possible, but in a number of cases, the spectrum width was reduced to 0 .25mm in order to permit the required exposure time to be decreased.
The photoelectric observations were made with the 32-inch telescope at the Fan Mountain station of the Leander McCormick Observatory, University of Virginia. The photometer is a single-channel device with a temperature- stabilized d.c. amplifier and integrator. In order to decrease the possi bilities of contamination, all observations were made with either a 10" or 15" diaphragm.
Microdensitometer tracings of the Perkins plates were made at George town University Observatory. Tests showed that the total instrument mean error due to non-linear effects and power supply fluctuations was less than
+7$ of the 100$ chart deflection. It should be noted that as much as one- half of the quoted error may be due to the uncertainty in the neutral density filter calibration. Individual tracings were repeatable to
13 14 better than +3$. The density tracings were then reduced to digitized intensity data using a Gerber GOAT. The GOAT is a portable, digitized, one-dimensional micrometer especially suited for measuring chart recordings.
The digitized intensity values were then used to construct line profiles from which the equivalent widths and half-intensity-widths of particular lines were found. For the H-gamma lines, the profiles were drawn free-hand out to 300-400 A on either side of the line center. The assumed continuum level was then drawn in. The enclosed line areas were measured with a polar planimeter. Similar profiles were constructed and measured to obtain the half-widths.
Radial velocities for each component were determined from single plates using lines in the 3600-4-500 A range. Line measurements were obtained using the SC0DD0 measuring engine at Perkins Observatory. Initial reductions were carried out at Indiana University by Ted Fay. The results were examined and lines having residuals greater than 5 times the variance were omitted. New averages were taken and radial velocities for each plate were then derived.
Photoelectric Am, H-beta, and H-gamma indices were obtained using a refrigerated 1P21 and an unrefrigerated EMI 6256 SA phototubes. The filters and photometer have been described elsewhere (Wood, 1965; Berg,
1966). The photometer tracings were reduced using a magnitude ruler
(Hardie, 1962). H-beta index transfers from the Virginia system to the
Crawford system were provided by Dr. II. John Wood. Transfer from photo electric H-gamma indices to the Petrie system H-gamma equivalent widths was determined indirectly by using the correlation between H-beta and
H-gamma indices, the correlation between H-beta indices given by Fernie
(1965) and the Petrie equivalent widths for the same stars (Petrie, 1965).
Except for the radial velocities, the remaining data reduction was 15 carried out on the B5500 computer at the University of Virginia Computer
Science Center. The CSC grant which made this possible is gratefully acknowledged.
Standards and Transfers
Table 3 lists the MK spectral classification and axial rotation standard stars used. The V sin i values listed are values given by Boyar chuk and Kopylov (1964) rounded to the nearest 10 km/sec. The MK standards are those given by Johnson and Morgan (1953)* Various standards used to calibrate half-intensity width measurements as well as those used for detailed microphotometric spectrum comparisons are indicated.
The Petrie system of H-gamma equivalent widths was originally defined for stars in galactic clusters and associations. It has not been extended to a sufficient number of MK standard stars for which
Perkins plates were available to permit a direct transfer to be made at the dispersion of 40 A/mm, however. Thus it was necessary to attempt an indirect transfer. First the equivalent widths for thirty M standards were found from the Perkins plates. Stars in the Petrie lists which had assigned MK types were then grouped according to spectral type and lumino sity. If a group had the exact MK type of one of the standard stars, the
Petrie equivalent widths were given weight five in the regression. A few stars had spectrograms taken at both Perkins and Victoria and were given weight ten. Several of the standard stars did not have corresponding
Petrie stars of the same MK type. In these cases, mean equivalent widths were interpolated from smoothed curves relating Petrie equivalent widths and MK spectral types for a given luminosity class. These were given weight two. The best fit between the Petrie system and equivalent widths obtained from Perkins plates was found to be linear. Sixty-three 16 points were used.
(Meisel) = (0.56+0.03) + (1.2+0.4) Hy (Petrie) Q = 1.5 2
Although the regressions are linear, there is not a one-to-one corres
pondence. This is not surprising since the Petrie equivalent widths have had contributions due to non-hydrogenic elements removed (Petrie, 1965)
and those obtained from Perkins plates have not. The placement of the
assumed continuum also may not have been the same in the two cases.
Since photoelectric indices do not have non-hydrogenic contributions re moved, one might expect the equivalent widths derived here to have a higher degree of correlation with the photoelectric values than the Petrie
system ones. As will be seen later, this is indeed the case. Difficulties were experienced with the Petrie system also when an absolute-magnitude
conversion was attempted. Thus the indirect transfer to the Petrie sys
tem is not considered to be very satisfactory.
The H-gamma equivalent width-photoelectric index transfer also had
to be made indirectly. First a transfer between the Petrie system and
the Crawford H-beta system (i960) was investigated. Using stars which
Fernie (1965) and Petrie had in common, the following least-squares
regression was found,
E.W. HY (Petrie) = (39.8+0.1) Hg - (99.6+0.07) 0 = 0.2 £
Then using the unpublished transfer found by Wood for the Virginia-
Crawford indices and a least-squares correlation between the Virginia
H-beta, H-gamma indices, an indirect transfer of the Virginia H-gamma
index and the Petrie equivalent width was found,
E.W. Hy (Petrie) = (63.3+0.2) Hy (Va) - (125.2+0.05) a = 0.4 1
(It is interesting to note that the Petrie-Fernie transfer analysis shows that the mean absolute-magnitude calibrations of Petrie and Fernie re quire a mutual adjustment of (P-F) = 0™2 in order to make them agree.
Since neither Petrie or Fernie indicate the probable errors of their mean relations, it cannot be determined if the difference is significant.)
Even though the variance of the transfer seems fairly high, it is less than the photographic transfer variance as well as the mean deviations of the average Petrie equivalent widths for a given MK spectral type. A correlation analysis showed that the equivalent widths obtained from the photoelectric H-gamma indices were better correlated with the widths found from Perkins plates than those corrected to the Petrie system in spite of the fact that the Petrie widths were used in the transfer.
Finally, the transfer between the H-gamma equivalent widths using Perkins plates and the Virginia H-gamma indices was found directly from this s tudy to b e ,
Hy (Va) = (1.92+0.02) + (0.02+0.01) Hy (Meisel) where 1.0 A < Hy (Meisel)< 18 A r= 0.96 + 0.01 , a =0.02
This relation is valid over a limited range of equivalent widths as in dicated. If the equivalent width is too large, the filters become satu rated and the photoelectric index is no longer linearly correlated with equivalent width.
Data Comparisons
Before giving the results of the observations in detail, it is useful to briefly compare them with the data obtained by others. Figure 1 shows the MK spectral types obtained from the Perkins plates compared with those given by Johnson and. Morgan (1953) or by Jaschek et al. (196*+). The criteria given by Jaschek et al. were used to decide the most reliable classifications of those listed for non-standard stars. Figure 2 shows a similar comparison between assigned luminosity classes. Only stars earlier than G5 are shown since later types are not frequent enough in this study to make meaningful comparisons. In Figure 3» the assigned
V sin i values are compared with the entries in the Boyarchuk and. Kopylov catalogue (1964). Figure 4 shows the comparison between the photoelectric
Am's obtained for this study and the Wallenquist im's in his general catalogue (1954). For further comparison, the A m ’s given in the ICDS are plotted with the photoelectric ones in Figure 5« Although there is no distinct systematic trend, the scatter is considerable. Thus ICDS magnitude differences should only be used when other magnitudes are not available or cannot be obtained. Ten such cases occur for pairs of small separation in the present sample.
The accuracy of the photoelectric Am values are not as high as one might expect from recent work on photoelectric photometry of single stars. There are several possible reasons for this. No attempt was made to remove the contributions of contamination except by using a small diaphragm (10"-15" of arc diameter). As well as cutting down the con tamination, the small diaphragms cut down the sky contribution. It was assumed that for the stars measured, the sky contributions would be small.
In order to cut down the observing time, the sky was checked only occa sionally during the course of the night. In addition, the problems of using small diaphragms for even single stars are well-known. Thus it was decided that if there was satisfactory agreement with the Wallenquist catalogue for stars in common, the accuracy obtained would be satis factory for the purposes of this study. The mean departure between those obtained and the Wallenquist values was -0.04+0.04. In view of the 19 TABLE 3. V SIN I,SPECTRAL CLASSIFICATION (MK) STANDARDS USED IN THIS STUDY Star MK Type V'sln .1 Notes (km/sec)
HD 195592 09.5 la 90 a Cam 09.5 la 15 Sgr BO la 69 cyg BO lb HD 194839 BO. 5 la 90 HD 14052 B1 lb HD 190603 B1.5 la 20 HD 193183 B1.5 lb 70 HD 13854 B1 lab 40 HD 13866 B2 lb HD 14134 B3 la 55 Cyg B3 la 0 HD 13267 B5 la 67 Oph(br) B5 lb 0 HD 199478 B8 la HD 14322 B8 lb HD 12753 A1 la a Cyg A2 la 20 HD 13476 A3 lab 89 Her F2 la 20 16 Sgr 09 II 6 Ori 09.5 II HD 199216 B1 II 70 HD 14357 B2 II E CMa B2 II 40 Y CMa B8 II 20 V Her F2 II 30 41 Cyg F 5 II 10 HD 193443 09 III i Ori 09 III 120 HD 13743 BO III HD 48434 BO III 70 K 1 w h* t-^ roM w w w w w row Aql BO.5 III 280 i— HD 13051 B1 III HD 14250 B1 III a Sco B1 III 50 HD I3890 B1 III o Per B1 III 150 Y Ori B2 III 60 12 Lac B2 III 80 ' Ori B2 III 40 6 Per B5 III 260 \ Aql B5 III 100 X Ori B5 III 30 3 Tau B7 III 80 Y Lyr B9 III 90 6 Cyg B9.5 III 130 a Dra AO III 0 TABLE 3 ~ Continued
Star MK Type V.sin i Notes (km/sec)
CT Gem A3 III 130 1,2 Y Oph A 5 III 250 1 Y Boo A7 III 130 1 Y Her A9 III 150 1 HD 14422 BO IV pe HD 13621 BO.5 IV 2 HD 13969 B1 IV 2 T Her B5 IV 20 e Gem AO IV 2 HD 14434 06 2 C Oph 09.5 v 400 1 HD 34078 09.5 V 0 1,2 T Sco BO V 10 6 SCO BO V 180 1 V Ori BO V 40 2 40 Per BO. 5 V 60 2 (0 Sco B1 V 150 1,3 . e Sco B2 V 80 3 n Hya B3 V 140 1,3 HD 178849 B3 V n UMa B3 V 210 1 HD 191263 B3 V X Cyg B5 V 140 2,3 a Leo B7 V 350 1,3 e Peg B8 V 3 a Del B9 V 160 1,2,3 a CrB AO V 140 1,2 a Lyr AO V 0 1,2,3 109 Vir AO V 340 HH 3314 AO V 120 Y Oph AO V 210 1 HR 6070 AO V 39 Dra (br) A1 V 180 1,3 HR 7784 A1 V 2 i Ser Al V 110 2 HR 5859 AO V 2 0 Leo A2 V 0 3 Leo A3 V 110 X Gem A3 V 150 2 6 Leo A4 V 190 1 80 UMa A5 V 250 1,3 21 LMi A7 'V 170 1 i UMa A7 V 140 1,3 P Gem PO V 70 1 a Boo F2 V 0 1 78 UMa F2 V 100 1 45 Boo F5 V 50 Y Ser F6 V 20 3 0 Boo F7 V 30 1,3 21 TABLE 3 - Continued
Star MK Type V. sin 1 Motes (km/sec J""
12 Com Composite 20 1^ Com A-shell 230 C UMa (ft) Am 70 1 17 Com AOp 30 1
Late-Type Standards (MK)
Star MK Notes
n Cas A GO V Ganymede (Sun) G2 V K Cet G5 V 3 5^ Psc K0 V 3 61 Cyg A K5 V 3 0 Aql G8 IV n Cep K0 IV 3 HR 1327 G5 III Y Tau K0 III 3 a Tau K5 III 3 6 And K3 III 3 0 And MO III a Sge GO III 0 Set G5 III 3 0 Lyr K0 II 3 M Per GO lb 9 Peg G5 lb Cap K1 lb 3
Notes to Table 3 1 Half-intensity width Hotation Standard 2 H-gamma equivalent-width Standard 3 Microphotometric Classification Standard 22
'JASCHEK OR JOIINSON-MORGAN G5 CLASSIFICATION GO r • • F5
PO
A5
AO
B5
BO •fi o 0 «*>• | | j i | | 05 05 30 35 AO A5 TO F5 GO G5
MEISEL CLASSIFICATION
Figure 1 - Correlation Between.Spectral Types 23
JASCHEK OR JOHNSON-MOROAN CLASSIFICATION • •
lb
II
III
IV
V
V IV III II I MEISEL CLASSIFICATION
Figure 2 - Correlation Between Luminosity Classes
WALLENQUIST AMV minus MEISEL AM..
-0.6
-0JI
-0.2
0.0 • •
+0.2
+0.^ 1 ____L 2m 6m 8m
fFJSEL AMy
Figure 3 - Magnitude Difference Residuals as a function of Photoelectric AM„ V sin i (km/sec) MEISEL 500
400
300 fr
200 i
100
3 >
ousuiuiuuji 100 200 300 400 500 V sin i (km/sec) BOYARCHUK and KOPYLOV
Figure 4 - Correlation of Rotational Velocities 25
VISUAL MAGNITUDE DIFFERENCE (INDEX. CATALOGUE) y lil
feWnrjiiniiM
PHOTOELECTRIC MAGNITUDE DIFFERENCE MEISEL
Figure 5 - Correlation Between Magnitude Differences Photoelectric Equivalent Width (A)
Petrie System Meisel System
p Indicates Peculiar Star
IQ Fer B 29 Cyg A
© ©
lb 20
Photoelectric Equivalent Width (ft)
Figure 6 - Correlation Between Equivalent Widths 27 uncertainties mentioned above, the agreement is considered to be satis factory and any systematic effects which might be present are obscured by accidental and random errors.
The H-beta and H-gamma results are not easy to check. Earlier it was indicated that the observed H-gamma equivalent widths (Meisel) had a high
degree of correlation with the H-gamma indices (Virginia), provided that
filter saturation was not present. It is of interest, however, to check
the results of the Petrie-Fernie transfer. Unless otherwise indicated, the values for H-gamma equivalent widths which were obtained using the Femie-
Petrie transfer are called H-gamma (Photoelectric) equivalent widths.
Figure 6 shows the correlation between the photographic equivalent widths
(both direct and Petrie system values) and those obtained from the photo electric (Fernie-Petrie transfer) equivalent widths. A correlation analysis
of the points gives the following results.
Perkins E.W. r = 0.85 + 0.01
Petrie System E.W. r = 0.81 + 0.01
Although the Perkins value correlation is higher than that for the Petrie
system, neither is as high as the direct transfer. Again it is suggested
that the lower correlation of the Petrie system may be due, in part, to
the exclusion of non-hydrogen elements near H-gamma. For widths greater
than 12 A , the correlation becomes non-linear. The position of four
stars which fall considerably below the 45° line should be noted. Three
of these are peculiar A-type stars. It is suggested that the Balmer lines
of these stars have profiles which do not saturate the filters as do
normal stars. Although one star, 12 Lac B showed no obvious spectral
peculiarities, it appears that its Balmer line structure may not be normal.
For normal stars, however, saturation appears to limit the usefulness of 28 the Virginia filters for absolute magnitude work to stars earlier than
B8-B9 for main-sequence stars, or A1-A2 for giants.
Observational Data
The basic observational data obtained for this study are gathered in
Tables 4, 5> 6, and 7. Entries are grouped according to whether the sys tem is considered physical or optical. In Table 4 the data are grouped according to the source of the /\m. The columns give the star name, the accurate ^m, the Virginia system H-beta and H-gamma indices. Table 5 gives the Crawford H-beta index and its probable error, and the photo electric H-gamma equivalent width and its probable error.
For the photoelectric H-beta and H-gamma observations it was originally assumed that the sky contributions were negligible, so few Hg , Hy sky deflections were taken during the course of the night. When considerable scatter was noted in the equivalent width correlations, the assumption was checked by additional observations. For the faintest stars measured, the error contribution due to ignoring the sky was 0™005 or less.
Table 6 gives the star name, assigned MK type, the assigned V sin i values and probable errors, the rounded to 0^1, and ^m reference with
M=Meisel, W=Wallenquist, I=Index Catalogue, and BD=Bonner Durchmusterung.
Table 7 gives the photographic H-gamma equivalent widths (not reduced to the Petrie system) and the probable errors.
Certain MK classifications were quite difficult. In these cases, the assigned type was decided upon after a comparison between microphotometer density tracings of the stars and certain standard stars. These are indicated in the notes column as well as in the further notes. The y sin values are weighted means of five independent visual estimates and one microphotometer half-width measurement set. TABLE 4 - PHOTOELECTBIC DATA
A. Stars with Photoelectric Ain's (Physical Pairs) (Wallenquist Values in Parenthesis)
Virginia Indices Star A( Am) B1+2.000 yl+2 . 00(
15239 A 1.880 2.030 D 2.71 ±0.04 2.060 2.223 B 1.43 ±0.02 2.025 2.144 C 2.44 ±0.04 1.955 2.110 15238 A -0.16 ±0.01 1.885 2.080 B 2.64 ±0.03 2.000 2.230 18473 A 2.004 2.201 B 1.62 ±0.03 2.463 2.035 IQ Per A 1.955 2.095 B 1.56 ±0.03 2.055 2.230 37330 A 1.930 2.125 B 0.66 ±0.02 2.030 2.147 S Mon A 1.815 1.925 C 4.19 ±0.0 3 I.929 2.080 D 5.69 ±0.04 2.405 2.015 1.980 , ,El 5.67 ±0.03 2.130 (Ei)E2 -0.27 ±0.03 2.025 2.135 P1 4.45 ±0.03 1.930 2.055 ±0.04 2.027 2.160 (pi;,Fs +0.93 a 5.35 ±0.03 1.940 2.060 149632 1.980 2.100 149631 +0.06 ±0.01 2.095 2.190 y Sgr A 1.965 2.010 E 5.51 ±0.02 1.978 2.110 D 5.96 ±0.03 2.015 2.190 B 5.05 ±0.04 — — — — — — _ _ I87566 A i 1.990 2.141 B 2.11 ±0.02 C 3.77 ±0.03 190918 A 1.797 1.970 D 4.73 ±0.03 — — P 0.64 ±0.02 1.880 2.020 B 4.30 ±0.04 . C 3.05 ±0.03 _ _ _ _ 190919 0.93 ±0.03 1.895 2.040 227634 A 1.910 2.030 D 0.97 ±0.03 1.900 2.055 C 3.96 ±0.03 B 3.51 ±0.02 — _ _ _ a' Cap A —— — — B 5.13 ±0.02 193322 AB 1 1.910 I.890 C 5.22 ±0.03 1.950 2.130 D 5.36 ±0.02 1.950 2.120 3 Cap A — — 30
TABLE 4 - Continued Virginia indices Star Am tL m ) /+2.000 yl+2.000
B 2.98 ±0.03 2.120 2.232 C 5.30 ±0.03 V389 Cyg AB 2.050 2.175 C if. 67 ±0.03 —— ------D 5.82 -0.02 —— ------
e Cap A 1 2.415 1.995 B 3.98 ±0.03 ------
12 Lac A 1 1.885 1.955 B 5.33 -0.04 2.005 2.340 AH Cas AB 1.950 2.095 C 2.22 £0.03 2.050 +2.227 c c 5.59 Jo. 04 ------— — — — D 6.33 ±0.04 2.200 2.200 E 6.16 Jo. 03 1.990 1.950 F 5.96 ±0.03 1.890 2.100 B. Stars with Wallenquist Ain's (Physical Pairs) (Meisel Values Given in Parentheses)
3266 A .. — mm> — — mm — — — B 0.80 ±0.05 — — — — a Cas A (6.68) (±0.02 ) ------— — — — — — C 6.67 ±0.03 ------9311 A ------— — — — B 2.56 ±0.20 ------— — _ — « i Cas A _ mm mm mm mm B 3.58 ±0.03 mm mm mm mm n Per A (4.65) (±0.05) ------— — — — B 4.72 ±0.13 1.980 2.177 23439 A ------— ------B 0.55 ±0.02 ------mm m. mm mm 23675 A ------— m m ------B 2.70 Jo. 39 ------— — — — 23 Ori A (2.19) (Jo.03) 1.870 1.985 B 2.12 ±0.09 1.880 2.040 v Gem A (3.84) (±0.04) 1.860 2.025 B 3.76 ------2.020 2.170 3 Mon A mm M mm mm$ B 0.46 +0.04 — — — — m m — mm mm C 0.38 ±0.05 mm — mm — 45995 A 1.750 1.935 B 2.88 ±0.07 1.950 2.120 2 Com A — _ _ _ B 1.44 — ------mm mm mm mm h Cen A — — — — B 3.71 ±0.08 — — — — 159481 A (2.98) (±0.06) ------— — — — — B 3.05 ±0.15 ------d Ser A _ _ _ _ mm — — — 31
TABLE 4 - Continued Virginia Indices Star Ain______a( A m ) ^ + 2.000 y1 + 2 .0 0 0
B 2.30 *0.15 — —— _ 179957 A —------B 0.25 ±0.03 — — _ — 184360 A ------B 1.56 *0.09 — — — — 191566-7 A B 0.90 ±0.05 — 206267 A ------D 2.37 ±0.11 —— 10 Lac A (5.26) (±0.06) 1.885 1.960 B 5.22 ±0.18 2.045 2.180 215812 A B 0.27 ±0.05 203374 A (3.^3) (*0.05) ------B 3.28 ±0.29 59 Cyg AB 4.42 ±0.08
C. Optical Pairs'-Meisel Photoelectric (Wallenquist Values in Parentheses)
16429 AB 1.910 2.005 C 3.20 ±0.03 2.000 2.300 26906-7 A 2.045 2.170 B 0.95 ±0.02 1.820 2.000 48279 AB 2.905 2.055 C 2.22 ±0.03 2.060 2.200 r, Gem A _ _ _ _ B 5.7^ ±0.03 —----— n CMa A 1.815 1.920 B 4.85 ±0.03 2.060 2.200 29 Cyg A 2.080 2.287 B 1.69 ±0.02 _ _ _ _ 69 Cyg A 1.850 1.995 C 4.49 ±0.03 1.950 2.070 EN Lac A (3.67) (±0.04) 1.898 2.067 B 5.8 5 ±0.02 1.910 2.000 C 3.72 ±0.03 1.905 2.030 D. Optical Pairs - Wallenquist Am's (Meisel Values in Parentheses)
9 Dra A (3.45) (±0.04) B 3.42 ±0.02 x Cyg A B 5.31 ±0.30 69 Cyg A B 5.29 ±0.10 213470-1 A 32
TABLE 4 - Continued Virginia indices Star Am A(Ajd) . b^+2.000 v1+2.000
B 3.83 *0.25 a Sco A (5.66) (±0.04) B 5.62 ±0.02 33
TABLE 5 H-Beta Indices and H-Gamma Equivalent Widths
Photoelectric Crawford Star 'AH3 E.W. A E.W. xio3 H-Gamma
A. Stars with Photoelectric A m's (Physical Pairs) (Wallenquist Values in Parenthesis)
15239 A 2.647 4 3.3 0.5 D 2.885 4 15.5 0 .8 B 2.839 5 10.5 0.7 C 2.746 7 8.4 0 .6 15238 A 2.654 6 6.5 0.5 B 2.805 4 16.0 0.9 18473 A 2.797 4 14.1 0.7 B 3.381 5 3.6 0.5 IQ Per A 2.684 5 7.4 0.4 B 2.811 4 16.0 0.9 37330 A 2.713 5 9.3 0.5 B 2.847 7 10.7 0.5 S Mon A 2.561 4 v ' too small C 2 .712 7 6.5 0.5 D 3.342 4 2.3 0 .6 Ei 2.780 5 9.6 0.5 (Ei)E2 2.839 5 10.0 0.5 pl 2.713 4 4.9 0.5 2.842 3 11.5 0.7 2.707 8 5.2 0.5 149632 2.715 4 11.8 0.5 149631 2.862 5 13.4 0 .6 u Sgr A 2.581 5 2 .0 0.5 E 2.576 . 3 8.4 0 .6 D 2.760 4 13.4 0 .8 D 1 1 •1 0 187566 A 2.728 4 10.3 1 1 1
B C 1 1 • 1 VT\ 1 0 190918 A 2.343 4 5.0 1 1 1 O1 • 1
nu 1 1 1 1 1
p 00 5 2.7 1 b 1 ro ro 1 • 1 1 ~o 1 VJ\ VJ\ 1 B C 190919 2.607 4 3.9 0 .6 227634 A 2.626 7 3.3 0.5 D 2.449 6 4.9 0.5 34-
TABLE 5 - Continued
Photoelectric Crawford Star He AHe. E.W. a E.W. X103 H-Gamma
C — — — — — — — B — ---- — — — a ' Cap A ------B — — — — — — ---- — — — 193322 AB 2.687 4 v ' too small C 2.741 3 9.6 0.3 D 2.739 3 9.0 0.4 0 Cap A - — — — — — — — B 2.894 5 16.1 0.8 C — — — — — — — —— — — — — V 389 Cyg AB 2.873 4 12.5 0.8 C ------D — — — — — — — — — — — — — e Cap A 3.268 5 1.1 0.2 B — — — — — — __ — — — — — 12 Lac A 2.654 5 Y ' too small B 2.813 4 22.9 1.0 AH Cas AB 2.739 3 7.4 0.5 C 2.872 4 15.8 0.9 CC' D 2.740 4 14.1 0.7 E 2.912 5 Y' too small 0.9 F 2.660 3 7.7 0.8
B. Stars with Wallenquist a i 's (Physical Pairs) (Meisel Values Given in Parentheses)
3266 A B « Cas A C 9 3 U A B i Cas A B n Per A B 2.715 3 12 .6 0 .7 23439 A B 23675 A B 23 Ori A 2.634 4 0.4 0.5 B 2.539 5 3.9 0.5 35
TABLE 5 - Continued
Photoelectric Crawford He AHg E.W. aE.W. Star X10- H-Gamma v Gem A 2.622 2.9 0.6 B 2.832 12.2 0.6 e Mon A B C 45995 A 2.476 4 Y * too small B 2.739 5 9.0 0.5 2 Com A B h Cen A B 159481 A B d Ser A B 179957 A B 184360 A B 191566-7 A B 206267 A B 10 Lac A 2.601 5 too small B 2.865 7 12.8 0.8 215812 A B 20337** A B 59 Cyg AB C. Optical Pairs-Meisel Photoelectric (Wallenquist Values in Parentheses)
16429 AB 2 .6 8 6 4 1.7 0 .6 C 2.806 3 20.4 1.1 26906-7 A 2.865 7 12.2 0 .6 B 2.479 4 1 .** 0.5 48279 AB 2.680 5 4.9 0.5 C 2.885 3 14.1 0 .6 £ Gem A B n CMa A 2.693 5 Y 1 too small B 2.885 4 14.1 0.7 36
TABLE 5 - Continued
Photoelectric Crawford H6 AH3 E.W. AE.W. Star______X103_____H-Gamma______29 Cyg A 2.843 2 19.6 0.9 B — - 69 Cyg A 2.608 5 1.1 0.3 C 2.740 6 5 .8 0.5 EN Lac A 2.666 4 5 .6 0.4 B 2.686 5 1.4 0.3 C 2.680 5 3.3 0.5 TABLE 6 - ASSIGNED SPECTRAL CLASSIFICATIONS AND ROTATIONAL VELOCITIES
Star MK Type V sin i _aM__ A. Physical Pairs
1 3266 A F5IV 150 B A9V 150 0.8 2 a Cas A K2II s-50 B K2IV-V <50 6.7 3 5005 A 06 110+20 D 08 220+10 0.8 C 09.5V 70+10 1.4 4 9311 A B5Iab: ^50 B B3IV:p 170+20 2.6 C B3IVsne 320±30 3.6 5 i Cas A A5p(Sr) 1 6 0: C G7V ^50 3.6 6 15239 A B4IV:sh 280*10 B B6V 80±10 1.4 15238 B3V:pnnsh 400+30 -0.2 7 n Per A K3Ib B AOVn l60±10 4.7 8 18473 A AOp(Si) 60*10 B A8V: 90*10 1.6 9 23439 A G8V <-50 B K3V 150 0.6 10 23675 A B0.5H: 150 B B3V 120*10 2.7 11 IQ Per A B8Vp: 100: TABLE 6 - Continued.
Star______MK Type______V sin 1______VM
B AOVnp: 200*20 1.6 12 37330 A B5V 150*20 BB8V:(e)nn 300*30 0.7 13 23 Ori A BllVnn 350*50 B B3 Vnn 370*10 2 .1 14 v Gem A B6IV:(e)p 250*20 B A1V 150*10 3.8 15 S Mon A B4lV:nne 350*50 B B2V 130*10 0.5 C B4lV:nne 370*50 0.4 16 45995 A B3IV:nne 320*20 B B8Ve: 220110 2.9 17 46056 A 08 190*20 B B2III 7 0s 1.4 18 S Mon A 0?P 6 0: CB8V 150*20 4.2 DA6III 120: 5.7 19 S Mon E2 A0V 140*10 5.4 20 50123 A B6Vnpe 300: B B9V: 170*20 2 .6 21 2 Com A FOIVip:: s.50 B A9V ^50 1.4 22 h Cen A B4IV i.50: B A0-A6-A7 70*10 3.7 23 TW Dra A A9V 150 B F7V *50 1.0 24 149632 Allp:: 70*20 TABLE 6 - Continued
Notes/ AM Star______MK Type______V sin i______a m ______Reference^
149631 A2V 80s 0.1 M 25 159481 A F7V 150 B K3V: 150 3.7 W 159482 F9Vp: i-50 0.7 I 26 y Sgr A .B8lap 150^ n E B2V 200*10 5.5 M 27 d Ser A AOVn+GO 300*10/80: n B F5V <50 2.3 W,f 28 178001 A A2V+Ap 70: n B A0-A1-F6 80: 0.5 I 29 179957-8 G3 V -50 B G4V 150 0.3 W 30 184360 A A3n(Sr) <50 n B F3V 150 1.6 w 31 187566 A A0p(si) 70*20 n C B8pe 400:: 2.1 M.b.f 32 189783 A F5V 150 n B F7V 150 0.2 I 33 190864 A 06 120*20 n B B0.5Vp: 60*20 0.5 I 34 190918 A 09.5Ia+WN5 130*20/3 2 0: n D B3V 280*20 4.7 M F Blla 50*20 0.6 M 190919 Bllb 70: 35 227634 A BOII-III; 80*10 n D B1V 400*20 1.0 M 190918 A 09.5Ia+WN5 130*20/320: -1.2 M 36 191566-7 A BOIVp 140*30 n TABLE 6 - Continued
Notes/ AM Star MK Type V sin i AM fieferenceg
B B1V 140*30 0 .9 W 37 a * Cap A G3Ib ^50 B K5III -50 5.1 M 38 193007 A Bill 120*10 n B BOIVp 50*10 0.5 I 39 193322 A 08 130*20 n C B7Vp:(e) 380*20 5.2 M D B8Vp:(e) . 310*20 5.4 M -40 6 Cap A AOV:+G5HI 120*30/50*20 B A2V 100*10 3.0 M 41 59 Cyg A BlIV:nne 420*50 n,i B A8III 100*30 4 .9 w,f 42 V 389 Cyg A B8Vp: <50: n B AOV 80*30 2.3 W C K1III <50 **•7 M,d 43 203374 A BO.5IVnne 400: n B B2 V* 180*20 3.3 W 44 E Cap A B5Vrnnesh 370*30 n B K1III-IV: <50, 4.0 M 45 206267 A 06 130*10 f D B2V+ 300*20 2.4 W C B1.5:IV 80*10 2.4 I 46 210940 A MOIII+ 150 n,f B K3III 15° 0.5 BD,f 47 10 Lac A 09V 60*20 n B A6III, IV 150*20 5.2 W 48 12 Lac A B2III 150 n TABLE 6 - Continued
Notes/ Am Star MK Type V sin i a m Reference®
B A3V 90*20 5.3 M 49 215812 A G2V -50 n B G3V -50 1.6 W 50 AR Ca.s A B3V 160*20 n C AOVn 230*20 2 .2 M B. Optical Pairs for All Components Studied 0-1 1810 A BOIVp 200*10 n B A9V 150*20 1.5 I 0-2 16429 A O9.5IH 140-10 B F4V ^50^ 3.2 M 0-3 26906-7 A B2III:nnep 290*30 n»i B A2-A2-A7 150 1.0 M 0-4 48279 A 08 60*30 B F2V 150 2 .2 M 0-5 52504 A BlVsnnp 350*30 n B KOIII-IVp 150 0 .9 I 0-6 c, Gem A G3Ib: <50 B G1V i50 5.7 M 0-7 n CMa A B5Ia 150 B AOV 150 ^.9 M 0-8 0 Sco A B1III 150 n B B8Vp 150 5 .6 W,c,f 0-9 0 Dra A G9IIIp 150 n B K3IIIp 150 3.4 W 0-10 RY Cap A FOV 150 Var. I TABLE 6 - Continued
Notes/ AM Star MK Type V sin i am References
0-11 29 Cyg A A0p(*Boo) 80±20 B K1III 150 1.7 M,f 0-12 V Cyg A G8IV 15° Var. I 0-13 1 Cyg A B5V 130^20 C K2III-IV <-50 5.3 W 0-1^ 69 Cyg A BO lb 90+10 B F7V 150 5.3 w 0-15 213^70-1 A3 la 150 n KOIIIp 150 3.8 W 0-16 EN Lac A B2III: 150 n C F5V 150 3.7 M C. Other Optical Components
S Mon Ei B5V 280±10 5.7 M 187566 B K2^ 150 3.8 M V 389 Cyg C K1III <-50 4.7 M Notes for Table 6 a _ E1-E2 form close optical pair; Contamination of H®, Hy Photometry likely, b - Helium Deficent Star c - Companion may be composite d - Component Optical e - HY Peculiar. f - Assigned spectral type and Luminosity Class confirmed by microdensitometer tracing comparisons. TABLE 6 - Continued
Notes for Table 6 - Continued g - Capital letters indicate magnitude reference (see 'below) i - Luminosity Higher than class V indicated by 3995A009 3995A026 ratios, n - See Additional Notes for further description of Spectrum. I - ICOS Am
M - Meisel Am \r A m references W - Wallenquist Am BD- Bonner Durehmusterung 44
Table 6 Additional Notes
3 HD 5005 - The derived H-gamma equivalent widths are not consistent with assigned spectral types. ^ HD 9311 - Absolute magnitudes of all three components are uncertain. Since the companion absolute magni tudes are completely unknown, the B5lab absolute magnitude was for calibration. The C companion may be as luminous as III, but no standards were avail
able at this type so IV was assigned. H-beta and
H-gamma show emission. The ^3995 (Nil) line is pecul iar (due to luminosity?). The B component had a num
ber of suspected peculiarities, but an unidentified feature near JJ460 (OII-FeIII(?)) is the most obvious.
5 HD 15089 ( iCas). The primary is an A5P strontium star with Cr and Eu present. 6 HD 15238-9 - There are at least four other members of this system, only one of which is listed in the ICDS. In the brightest component, HD 15239» shell lines were noted down to H-zeta. No emission was
visible. In HD I5238, all hydrogen lines down to the
Balmer limit appear to have shell cdreB'. 0 II at ^3^9 also appears narrow.
7 HD 17506 (n Per) - The primary is an MK standard. This pair has been studied using UBV photometry by
Tolbert (196^).
8 HD 18^73 - The primary is an AOp silicon star with 4077 (Cr II - Sr II) faint, Ca II abnormally faint, and Mg II 4481 faint. Balmer lines fairly weak.
Plate of companion is fogged and has some flaws, but microphotometry comparisons confirm the assigned type.
10 HD 23675 - According to the Morgan-Code-tfhitford cata
logue (1955)9 the primary is of type BO.5 III, but 4-089 (Si IV) is much too strong compared to 4072
(0 II), 4120 (Si IV, He I). Hence luminosity class II was assigned here. 11 IQ Per - The H-gamma equivalent width indicates primary luminosity is higher than class V. The primary is an
eclipsing variable, but only single lines are visible on the Perkins plates, although the Balmer lines have
broad wings and the Ca II lines are diffuse.
12 HD 37330 - H-beta of secondary may be in emission.
13 HD 351^9 (23 Ori) - System previously studied by Slettebak (I963). 14 HD 45542 (w Gem) - Only H-beta shows emission (weak). The other Balmer lines down to H-zeta have deep cores
probably due to a thin shell. Several weak lines
around H-delta are abnormally faint- compared to ratios in the standards.
15 HD 45725 (& Mon) - The A component of this system has been extensively studied by McLaughlin (I96I, I95I).
This system is listed in the Merrill and Burwell
catalogues (1933, ^943, 19^9) with two components given as Be, but the Yale Bright Star Catalogue lists 46
all as Be. The Cowleys (I966) have pointed out that the B component did not have emission on plates taken
by them. The placement of the components makes it very difficult to obtain uncontaminated spectra. On
Perkins plates taken in I965, the B component is com paratively slowly rotating with an estimated V sin i near 130 km/sec. No emission was detected. It is interesting to note that the faintest component is
the most rapidly rotating. The A and C components
were assigned the same spectral type and luminosity class although there are subtle differences between
them other than shell and emission features, in the
A component, H-beta shows single broad emission; H-gamma shows narrow double emission; H-delta shows
faint single emission. The Balmer lines become
increasingly narrow shortward of Hr,. In the component^ H-beta shows double emission with the blue line com
ponent stronger than the red; H-gamma shows single emission; H-delta shows only a faint shell line.
Emission is visible at 4650 (Fe II), 4580 (Fe II), and on the blue edge of 4387 (Fe II). 16 HD 4-5995 - The spectrogram of the secondary was fogged
unfortunately. However, an intercomparison of micro- photometric tracings of the unknown and standard stars
verified the assigned type. H-beta appears to be in
emission on the tracing so B8 V:(e) might be more appropriate. The primary shows H-beta in double 47 emission and H-gamma with faint single emission.
18 HD-^7839 (S Mon) - The component is the brighter component of a close pair which is ,Walker No. 179 in
N.G.C. 226k, It appears to be a B5 V star and there
fore is considered optical. The C component has a weak H-beta line suggestive of emission. Other Balmer lines are normal. All companions earlier than AO show Ca II Interstellar lines, but A shows only a
very weak Ca II lines. Yet there is little doubt
that the stars, except Ej_, are physically connected.
Although Morgan, Code, and Whitford (1955) give 06e for the A component, no emission is present on the Perkins plate. On the basis of the strength of the
He I - He II lines, an 07 classification seems appro
priate. 20 HD 50123 - This star is not listed in a recent survey of southern Be stars (Jaschek, Jaschek, and Kucewlcz,
196^), but is given by Merrill and Burwell (1933)* Because of the great southern declination of this
object, the spectrogram obtained of the companion was very faint. A microphotometer tracing verifies a
type of B9 V:, with Mg II faint compared to Ca II. The excellent Perkins plates of the primary taken by
Slettebak show complicated shell and emission struc ture; H-beta shows emission; H-gamma shows an‘ absorp tion core. There are numerous lines which are not present in any of the available standards between 4530 and 4650 and near H-gamma. Also Mg II 4481 =
He I 4471; emission was noted at 4950 (Pe II), 4923 (Pe II), 4894 (Pe II), 4887 (Pe II), 4520 (Pe II),
4351 (Pe II); the 4481 (Mg II) line has emission on the red edge. The 4236 line is flanked by two absorp tion coresJ
21 HD 104827 - Enhanced 4172 (Pe I) relative to 4226 (Ca I) and numerous lines between 4270 and 4330 indicate luminosity higher than class V, but no stan dards were available at class III, hence class iy was selected.
22 HD 120955 (h Cen) - The primary is a spectroscopic binary, although only single lines were noted. The
companion, however, is an Am star (AO-A6-A7) of 63
Tauri type. If a coeval hypothesis is assumed for the pair, then the Am star is still contracting
toward the main sequence. 23 TW Dra - This eclipsing binary was previously studied by Roman (1950) who finds the secondary of the eclip sing system to be subluminous. On the Perkins plates of the visual system, no trace of the subluminous companion could be found, although one plate was taken at the end of total eclipse.
24 HD 14963I-2 - The brighter component is a spectro scopic binary. The mean type is Al V, but the double
Ca II and Mg II lines Indicate unequal component brightness. 49 26 HD 166937 ( y Sgr) - This star is a spectroscopic
binary, but only a single set of lines was visible and a type of B8 lap was assigned to the primary. The complete absence of ^009 (He I) and the very weak ^387 (He I) are the most obvious peculiarities at ^0 S/mm, Indicating perhaps that the star is of class
B8 Ia+ . H-beta may be in emission, but the focus was poor in that region.
27 d Ser (59 Ser) - The primary is a known spectroscopic
binary and variable star, but it has not been shown to be eclipsing. The visual companion is only away so contamination is very possible. The system
was previously investigated by Tilley (19^3) who assigned the type AO to the faint companion. A third spectroscopic component was postulated to explain short period variations in the K-line velocity. Since it is not clear to which member of the spectro scopic binary the third component belongs, the config
uration of the system cannot be specified. It is possible that this third member is responsible for the
K-llne anomaly and the light variations, but more observations are necessary. The Perkins plate shows a composite spectrum of AO V plus GO. For the visual companion, the Perkins plate shows an P5 V star under
the dominating AO V spectrum. Since this AO spectrum matches that of the primary, contamination is certain ly responsible. The underlying spectrum, however, is 50
too early for GO and so In considered real and not due
to contamination.
28 HD I78OOI - The primary of this interesting system is
listed in the Pennsylvania eclipsing binary catalogue
(Koch, Sobieski, and Wood; I963) but it does not have an official I. A. U. designation. The visual system consists of an A2p (V) and an A0-A1-F6 metallic line star. For calibration purposes the primary was treat ed as an ordinary A2 V star. From its spectrum, how
ever, it is evident that it is peculiar. H-beta is weak and appears to be asymmetrical or double. H- gamma is not double, but appears asymmetrical with the
wings of equal extent, but a displaced core. H-delta
may be double. The K-line also is double. A group of
lines between 4-170 and 4-180 for which no plausible Identifications could be made are more prominent than
any other features between H-gamma and H-delta. The Fe II, Fe II-Ti II (4-172) doublet is particularly
strong. Since the Am visual companion is probably physical, this pair merits considerable future study. 30 HD 184-360 - High velocity stars.
31 HD 187566 - The B component is considered optical. The C component is very peculiar. No features other than Balmer lines are definitely present. The 4-881
(Mg II) line is so faint and broad that even half
width measurements could not be applied with certainty.
The microphotometer shows H-beta with emission. Ca II 51 and the Balmer lines Indicate B8 V, but He I is
totally absent. The dish-shaped Balmer and Ca II
contours indicate rapid rotation possibly In excess of
500 km/sec. If the line broadening Is indeed due only to rotation, this star may have one of the largest V sin i values yet found.
32 HD I89783 - The brighter component is a close visual
binary. 33 HD 190864 - The fainter component of the system may
be peculiar since some features suggested higher
luminosity than class V, but 3995 (N II) was absent so
V was chosen. The 0 II line at 4416 was particularly
anomalous, being too strong for the assigned type.
34 HD I909I8-9 - The bright components belonging to the
P Cygni association have been studied by Homan (1951).
HD I909I8 A is a spectroscopic binary. It consists of a Wolf-Rayet star and an 09 supergiant. Kuhi
(I966) lists the 0 star as an O9.5 III star. The Perkins plate indicates a classification of 09*5 la
plus a 1.7N5*5 which agrees well with an independent
classification by Hiltner and Schild (1966). The
plate shows broad faint emissions flanking H-gamma; . emission redward of H-beta; broad emissions (±12 X)
flanking 4600 (N II), 4615 (N II), and blueward of 4650 (C III). Extremely broad emission features
flanking a faint line 4686 (He II). It is not possi
ble to determine which star is fainter, but a Am less than one magnitude seems indicated. The F component
is subluminous for type Bl la compared to HD I909I9
which is Bl lb. The luminosity inversion between la
and lb postulated by Weaver and Ebert (196^) is not confirmed, however.
35 HD 227634 - The brighter component was classified as
BO.5 by Morgan, Code and Whitford (1955)> but the Perkins plate indicated BO II, although BO II-III is possible.
36 HD I9I566 - In the primary, H-gamma and He I 44-71 are double. The 0 II lines around H-gamma are faint, but visible. The red edge of the Balmer lines, partic
ularly H-beta and H-gamma are sharp. All Balmer lines show shading and asymmetry on the blue edges.
38 HD I93007 - The primary is not sharp-lined at 40 X/mm. The companion is peculiar, although if it is treated as a normal star, the calibration is not inconsist
ent. In particular, a line at 4550 (Fe II?) which appears to be luminosity sensitive in the standards
is much too strong relative to 4552 (Si II). On the other hand, 0 II 4-318 is too faint for the assigned type.
39 HD 193322 - The roational velocities of the two faint
er components are large (380 and JlQ km/sec). Inter comparison of microphotometric tracings of standards
star spectrograms with tracings of these stars con
firmed the assigned MK types, but certain peculiarities 53 were evident. In the D component, the
(He I - Mg II) lines are too weak and the silicon
lines are too strong compared to the stellar Ca II lines, in the C component, the helium lines are weak and silicon lines are too strong. It is possible
that both stars are helium and magnesium deficient, similar to the companion to HD 187566.
^1 HD 200120 (59 Cyg) - The primary of this system is a Be star that is variable in both spectrum and light.
Its rotational velocity is very high. H-beta shows
double emission; H-gamma has single emission; H-delta single emission asymmetrically placed with respect to the core; H-epsllon shows a single faint emission.
V 389 Cyg - The B component is considered optical. The primary is a known spectroscopic binary and var
iable star, but eclipses have not been established. The spectrum resembles IQ Per with extensive wings on
the Balmer lines. The stellar Ca II lines indicate type B8 V, but the Mg II ^ 8 1 is much too strong for
B8. Only a single set of lines was present. The
luminosity calibration and H-gamma equivalent widths indicate luminosity brighter than V. Hence the
notation p: was applied to the classification.
^3 HD 20337^ - The primary has H-beta with single emis sion; H-gamma with double emission; and H-delta, H- epsilon, H-zeta with single emission. 0 II around H-gamma is faint but definitely in emission. Also Pe II emissions at 4556 and 4577 are plain.
HD 205637 (e Cap) - Luminosity criteria for the com panion conflict. The assigned type of K1 III-IV is
considered a compromise. Some of the line ratios Indicate luminosity higher than III, but the plate is too faint to confirm this with a sufficient number of line pairs.
46 59°2485-8 - These stars share common proper motion,
although the separation is wide, 1 * of arc. 4-7 HD 214680 (10 Lac) - The primary is an MK standard.
Although the fainter companion has well-developed Balmer lines, other criteria indicate a luminosity
brighter than V, hence III, IV was assigned.
48 HD 214993 (12 Lac) - This star is a 3 CMa star and MK standard. It is virtually identical with aSco. 50 AR Cas - The primary is an eclipsing binary, but only a single set of lines was noted. The C component, If not optical, is subluminous.
0-1 HD 1810 - The brighter component shows line asymmetry
or emission and strong interstellar Ca II.
0-3 HD 26906 - The brighter star shows H-beta with double
emission; H-gamma is sharp, but with no emission;
emission occurs on the red edges of 4144 (He I), 4387 (He I), Luminosity of III is definitely Indicated.
The fainter optical component is an A3m (A2-A2-A7) with 4130 (Si II) absent. 0-5 HD 5250^ - The secondary may be a high-velocity giant. The primary does not show emission, in spite of its
high rotation rate. The most obvious peculiarity is a strong unidentified line near the interstellar K line.
0-8 HD 1^7165 (a Sco) - The primary is a g CMa variable and MK standard. Although the secondary is considered optical, it is of considerable interest. The mean
type B6 V was assigned, but a number of peculiarities are noted. Some of the anomalies might be explained if B5 V plus B8 V is assumed, but a number lines
between ^8*M)-^860 are not found in either of the assumed types.
0-9 o Dra - The primary is a spectroscopic binary. Low relative radial velocities are coincidental.
0-15 HD 213^70 - The CN break of the fainter component is anomalous.
0-16 16 Lac - The primary is a 8 CMa variable. 56 TABLE ?
H-GAMMA VALUES REFERRED TO THE PETRIE SYSTEM USING THE MK TYPE TRANSFER FORMULA
Photographic hy AHr Star E.W. E.W. A. Physical Pairs 1 3266 A B 2 a Gas A B 3 5005 A 5.8 0.1 D 4.2 0.2 C 4.2 0.1 4 9311 A 3.7 0.2 B 2.7 0.2 G 8.1 0.2 5 \ Cas A 12.2 0.3 G 6 15239 A 2.9 0.4 B 8.9 0.6 15238 shell 7 n Per A B 15.0 0.4 8 18473 A 5.2 0.1 B 9 23439 A B 10 23675 A 2.2 0.1 B 5.0 0.4 11 IQ Per A 5.1 0.3 B 12.4 0.1 12 37330 A 6.3 0.2 B emission 13 23 Ori A 4.1 0.3 B 5.3 0.3 14 v Gem A 6.2 0.2 B 14.0 0.3 15 6 Mon A emission B 6.4 0.2 C emission 16 45995 A 3.0 0.3 B 4.6 0.2 17 46056 A 3.0 0.1 B 5.7 0.3 18 S Mon A 3.8 0.2 G 11.6 0.4 19 S Mon ^2 8.8 0.1 20 50123 A 7.0 0.2 57
TABLE 7 - Continued
Photographic Hy AHy ______Star______E.W.______E.W. B Plate Fog 21 2 Com A B 22 h Cen A 6.9 0.2 B 7.6 0.3 23 TW Dra A B 24 149632 8.0 0.4 149631 21.8 0.3 25 159^81 A B 159^82 26 m Sgr A 2.2 0.2 E 4.8 0.3 27 d Ser A 6.2 0.2 B 28 178001 A 20.0 0.3 B 14.3 0.2 29 179957-8 B 30 184360 A 11.4 0.2 B 31 187566 A 8.2 0 .3 c 13.3 0.3 32 189783 A B 33 190864 A 1.4 0.3 B 6.3 0.4 34 190918 A 1.1 0.1 D 4.6 0.2 F 4.3 0.3 190919 3*3 0.2 35 227634 A 3*6 0.1 D 4.0 - 0.2 36 191566-7 A 2.8 0.2 B 3*6 0.3 37 a * Cap A B 38 193007 A 2.7 0.2 B 2.9 0.3 39 193322 A 3.6 0.4 C 6.9 0.3 D 5.3 0.4 40 & Cap A 4.0 0.2 B 58
TABLE 7 - Continued
Photographic Hy aHy Star E.W. E.W. 41 59 Cyg A emission B too late 42 V 389 Cyg A 12.4 0.4 B 14.2 0.1 C 43 203374 A emission B 6.0 0.1 bb £ Cap A 3.6 (shell) 0.2 B b5 206267 A 3.1 0.2 D 4.2 0.1 C 3.5 0.3 b6 210940 A B b? 10 Lac. A 3.2 0.2 B bQ 12 Lac A 3.7 0.2 B 18.0 0.2 b9 215812 A B 50 AR Cas A 6.6 0.3 C 28.2 0.4 B. Optical Pairs for All Components Studied 0-1 1810 A Peculiar Profile B 0-2 16429 A 2.3 0.4 B 0-3 26906-7 A emission B 9.9 0.3 o-b 48279 A 2.3 0.3 B 0-5 52504 A 2.4 0.3 B 0-6 C Gem A B 0-7 n CMa A 3.1 0.2 B 25.6 0.2 0-8 0 Sco A 4.3 0.2 < B 5.1 0.2 0-9 0 Dra A B 0-10 RY Cap A 0-11 29 Cyg A 11.9 0.3 B 59
TABLE ? - Continued
Photographic HIT AHy Star E.W. E.W. 0-12 u cyg A 0-13 X Cyg A 7.6 0.3 C 0-1^ 69 Cyg A 2.1 0.1 B 0-15 213470-1 2.7 0.3 0-16 EN Lac A 4.0 0.2 C C. Other Optical Components
S Mon E1 8.8 0.1 I87566 B1 V 389 Cyg C Single plate radial velocities were obtained for the purpose of checking physical relationships of companions. But because of the small number of lines measured they are not considered to be suitable as accu rate velocity determinations for these stars. A table of radial velo cities is therefore not included here.
Luminosity Classification of Be Stars
The spectral classification of Be stars is particularly difficult.
In the Be stars studied, here, the line ratios 3995 (N Il)/4009 (He I)
and 3995 (N Il)/4026 (He I) were the only ones that indicated luminosity differences. Because the changes were subtle, the assignment of class XV: or III: must be treated with caution. No standard luminosity ratios
other than 3995/4009 indicated luminosity higher than class V. At
40 A/mm, however, the 4009/4026 ratio itself appears luminosity sensitive between classes V and III. Some of the Be stars seem also to show variation of the 4009/4026. CHAPTER III
THE RESULTS AND DISCUSSION
Calibration of Absolute Magnitudes
Absolute magnitudes for components of special interest have been derived using MK types for "normal" companions, magnitude differences rounded to the nearest 0™1, and the MK absolute magnitude calibration given by Keenan (1963). In addition, absolute magnitudes based on photo graphic H-gamma equivalent widths and photoelectric H-gamma and H-beta indices have been obtained using the Petrie and Fernie calibrations for a number of the special interest stars. These data are gathered in
Table 8. The /^m-MK type values are considered to be the most reliable.
Values derived from hydrogen lines for Be stars are included for com pleteness only and to illustrate the effects of shell and emission lines.
They have not been used in the statistical treatment of the hydrogen line absolute magnitudes. Inconsistent values for stars which did not show line abnormalities on Perkins plates are indicated. Hydrogen-line absolute magnitudes for the companions used to calibrate the stars of special
interest are listed in Table 9 .
The photoelectric H-gamma indices were converted to the Petrie (1965)
system using the appropriate transfer formulas. Then the Petrie mean
relation was used without Petrie spectral-type corrections. Because of
filter saturation (see previous chapter) and the lack of suitable spectral-
type corrections for photoelectric indices, the H-gamma absolute magni
tudes cannot be considered very reliable. The H-beta indices were
61 TABLE 8
RESULTS o p a b s o l u t e m a g n i t u d e calibration op co m p o n e n t s of p a r t i c u l a r INTEREST. CALIBRATION SYSTEMS USED ARE SHOWN IN PARENTHESES
Mv using Mean M y Am and M K Spectral Absolute Magnitudes obtained from Type of Type ______Hydrogen Lines______companion (Keenan or Photographic Photoelectric Photoelectric fy Star MK Type (Keenan) Blaauw) H^(Petrie) Hg (Petrie) (via Petrie System)
5005 A 06 -5.9 -5.5 -2.8a 5005 D 08 -5.1 -5.2 -4.5 46056 A 08 -5.0 -5.2 -5.0 S Mon A 07P ~-4.1 ■< -5.1 -5.3 -3.7 -6.5 Y * too small -4.8 193322 A 08 f-5.8 -5.2 -4.6 f too small t-5.6 -1.5° Y 206267 A 06p r-4.9 -5.5 -4.5 -5.9 10 Lac A 09V 1-4.5 -4.7 -5.2 -4.0 Y t too small
15239 A B4lVssh -2.5 -1.9 -5.8b -1.4° -4.3* 15238 B3V:pnnsh -2.8 -1.7 -1.4° -1.7° 37330 B B8V:(e)nn -0 .4 +0.1 -0.6° +0.5° v Gem A B6lV:(e)p -2.6 -1.4 -3.5a -3.0° -3.1° B Mon A B4lV:nne -3.0 -1.9 B Mon C B4V:nne -2.6 -1.4 203374 A B0.5lVnne -5.8 -4.6 Mv<-7.5° Y » too small e Cap A B5V:nnesh -2.3 -1.0 My* +1.8 -5.0° 50I23 A B6Vnpe -2.6 -0.7 TABLE 8 - Continued
Mv using Mean My A m and MK Spectral Absolute Mangitudes obtained from Type of Type ______Hydrogen Lines______companion (Keenan or Photographic Photoelectric Photoelectric HY Star______MK Type (Ke enan) Blaauw) Hy (Petrie) HB(Petrle) (via Petrie System)
45995 A B3lV:nne -3.1 -2.5 -5»7b My<-7.5° y » too small 9311 C B3lVne -2.9 -2.5 -5.6b 59 Cys A BlVsnne -4.3 -3.6
190864 B B0.5Vp -4.4 -4.0 -5.0 -3.5 -4.1 191566 A BOlVp -4.4 -4.8 -4.3 9311 B B3lV:p -3.7 -2.5 -2.3 18473 A AOp(Si) +0.8 -3.7 Mv<-7.5 -3.6 184360 A A3p(Sr) +1.6 +1.1 2 Com A FOlVp: +1.6 h Cen B AO-A6-A7 +1.7 -2.3 1 Cas A A5p(Sr) -0.4
A -4.4 -5.2 23675 B0.511: “5 *5 227634 A B0II-III -4.5 -5-2 -5.5 -6.5 -3.2 193007 A BUI -5.1 -5.0 -5.6 12 LAC A B2III -3.7 -3.6 -5.2 -2.0 y * too small r09.5ia -6.3 ±90918 A- -7.6 -8.1 -6.4 My>+1.8 —9*0 IWN5 -7.0 v Sgr AB8lap -7.3 -8.2 -7.3 -5.4 -7.8
CT) CO TABLE 8 - Continued
Mv using Mean Mv Am and MK Spectral Absolute Magnitudes obtained from Type of Type Evdro&en Lines companion (Keenan or Photographic Photoelectric Photoelectric Hy Star MK Type (Keenan) Blaauw) Hv(Petrie) He (Petrie) (via Petrie System)
AH Cas A B3V -1.6 -1.7 -3.1 -0.1 -1.2 23 Ori A B H V -3.8 -4.1 -4.5 -3.8 -7.0° a Cap A G3lb -5.5 -4.5 a Cas A K2II -2.2 -2.0 n Per A K3Ib -4.1 -4.4 210940 A MOIII -0.7 -0.4 e Cap A A0V+G5 -1.5 + o . 6 (ao) -0.3 +1.2 ---- IQ Per A B8Vp: -1.0 +0.1 -4.2 -1.2 -1.3 v 3 8 9 c y g A B8Vp: -1.7 +0.1 +1.0 +1.2 +0.9 d Ser A AOV+GO +1.1 + o . 6 (ao) -3.5
Notes for Table 8 a - Absorption Cores Present on Spectrogram b - Emission or Shell Present on Spectrogram c - Line Anomalies are probably present 65 converted to the Crawford system and the the Femie (19^5) mean relation was used to obtain absolute magnitudes. Although there is no direct Hy equivalent-width calibration available from this study, filter saturation of the H-beta indices also seems likely to limit the accuracy obtained.
Comparison of the various absolute magnitudes show that even in the absence of detectable line anomalies, H-beta and H-gamma magnitudes appear to be useful only for statistical purposes.
Hertzsprung-Russell diagrams for the special interest stars have been constructed using the Am - MK type calibrations and are shown in
Figures 7 and 8. The Keenan (1963) sequences are also shown.
It was suggested in the previous chapter that the Petrie calibration presented some problems even when it was applied to normal stars. In
Figure 9. the correlation between the absolute magnitudes obtained from photographic H-gamma equivalent -widths and those obtained using the Am-
MK type calibration. The diagram shows that the O-type stars give H-gamma absolute magnitudes which are about -§- magnitude too bright relative to the Am - MK types while the other stars average about \ magnitude too faint. The latter result is not surprising since the Petrie system of absolute magnitudes was calibrated using galactic clusters which, as shown by Blaauw (1963)1 give a somewhat different MK calibration from that ob tained if field stars are used. The result for the O-type stars seems to indicate that the Petrie spectral-type correction of about one magnitude is not consistent with other spectral types. Thus if one wishes to con struct a consistent MK-type and hydrogen-line calibration, a systematic shift ( - 0^5) must be introduced to the cluster data or the Petrie system must be calibrated using near-by stars and mean parallaxes. This basic point must be kept in mind in all discussions of magnitude calibration. 66
la © P 09-5 I.
/
II-III
-21
Main
Seauence IV quence q Be stars p Peculiar stars PO sh shell present
+2 BO AoB8 FO •Soectral Type ■Figure 7 - H-R Diagram for Early-type Stars 67
lb Sequence
O lb
Ii Sequence
III
AO+GO ill Sequence
+2 g.A aaM ,intn.Tni7T' GO Gb K2 Kb MO Spectral Type
Figure 8 - H-R Diagram for Late-type Stars 68 TABLE 9 - ABSOLUTE MAGNITUDES DERIVED PROM HYDROGEN LINES FOR OTHER EARLY-TYPE STARS
Photographic Photoelectric Mv Mv (HB) Mv (Hy) Petrie Fernie Petrie Stax Calibration Calibration Calibration
5005C -4?2 9 3 H A -5.8 15239B -1.8 -0.2 n PerB +1.6 -0.8 +0.9 23675B -5.5 IQ Per B -4.2 +0.7 +1.4 37330A -3.5 -0.7 +0.2 23 Ori B -4.2 -4.0 -2.3 v Gem B +1.7 +1.0 +1.1 g Mon B -3.1 45995 B -5.2 <-8 +0.5 46056 B -3.1 S Mon C +1.2 -0.7 -1.0 S Mon E2 -1.5 +1.0 +0.5 h Cen A -2.9 149631 -2.3 +1.1 -0.2 vi Sgr E -4.1 -5.3 +1.1 178001 A +2.0 B +1.9 I87566 C +2.1 -0.5 +0.6 190864 A -5.0 -3.5 -4.1 190918 D -4.5 F -4.5 -4.7 -1.7 190919 -5.0 -3.7 -3.6 227634 D -4.5 -3.0 Y * too small 191566-7 B -4.3 193007 c -5.0 193322 C -3.1 -0.2 +0.7 D -4.0 -0.2 +0.4 V 389 Cyg B +1.0 203374 B -3.3 206267 D -4.9 C -4.3 12 Lac B +2.1 +1.0 +1.8 AR Cas C +1.7 +1.1 +1.8 16429 A -5.5 -1.2 -7.0 26906-7 B -1.2 +1.1 -7.3 48279 A -5.5 -1.5 -1.8 52504 A -5.6 n CMa A -6.2 -1.1 Y * too small n CMa B +1.7 +1.1 +1.3 a Sco A -4.5 a Sco B -4.4 TABLE 9 - Continued
Photographic Photoelectric Mv MV (HB) Mv (Hy ) Petrie Pernie Petrie Star Calibration Calibration Calibration
29 Cyg A +1.2 * Cyg A -2.8 69 Cyg A -5.5 -3.8 -7.9 213^70-1 A -8.5 EN Lac A -5.3 70 The Petrie calibration, however, is not as subluminous as the zero-age main-sequence (ZAMS) which is used as a reference level later in this
chapter.
For present purposes, the Keenan calibration of the luminosity
sequences will be used as reference levels against which the double star
calibrations can be compared.
It is of interest to now compare the results obtained for absolute
magnitudes from double stars to the MK type means. Table 10 lists the
mean departures from the MK calibration by Keenan (1963) or Blaauw (1963)
for various groups of stars. Although based on a small sample, the results
are considered significant.
First, the double star a m - MK type calibrations indicate that
uhe Be stars are over-luminous while the giants and supergiants are under-
luminous compared to the MK calibration. Secondly, the Petrie system with
spectral type corrections gives the 0-type stars subluminous while giants
and supergiants show zero-deviation. No comparison of the Be star hydrogen-
line was made since the values are obviously affected by line abnormali
ties. Lastly, all non-emission class V or IV stars were grouped together.
These show a significant departure from the mean for the H-gamma photo
graphic results which had Petrie spectral type corrections applied. Photo electric H-gamma values using the Petrie calibration, but without the
spectral type corrections showed results more consistent with the Femie
H-beta photoelectric results.
The rather large probable errors for the hydrogen-line mean-devia-
tions illustrates once again the high risk of using H-beta or H-gamma
as the sole criterion of luminosity for stars which show no emission.
Even for limited samples like the one considered here, the problem of 71
TABLE 10 - MEAN DEVIATIONS OF CALIBRATED ABSOLUTE MAGNITUDES FROM MK MAIN-SEQUENCE GIVEN BY KEENAN (1963) AND BLAAUW (I963)
Group (Observed Number Calibration Stars-MK) of Stars System Be -1.0*0.2(p.e.) 10 companions
0 stars 0.0*0.2(p.e.) 7 companions Early-type Giants and Supergiants +0.6*0.2(p.e.) 6 companions
0 stars Petrie 0.9-0.5(p.e.) 7 Photographic Early-type Giants and Supergiants 0.0*0.6(p.e.) 6 Petrie Photographic All Non-Emission, Early-type stars Near Main-sequence: -0.8±0.5(p.e.) 34 Petrie Photographic E.emld" 0.0*0.6(p.e.) 35 Photoelectric Petrie -0.2*0.5(p.e.) 25 Photoelectric 72 differences between cluster and field star absolute magnitudes is evident. Since the double stars are mainly field stars, agreement with the Keenan calibration would be expected. On the other hand, the devia tions of the Petrie photographic H-gamma absolute magnitudes (Figure 9) are presumed to be the result of the use of cluster stars for the initial calibration. Weaver and Ebert (1964) have attempted an MK reealibration, but their results do not resolve this particular difficulty.
No reliable comparisons for the O-type stars and early-type giants and supergiants could be obtained between the MK calibration and the results for the photoelectric indices because of very small samples. For stars near the main-sequence, agreement between the MK calibration and the photoelectric values is considered very good. This is curious since the photoelectric absolute magnitudes were obtained using relations cali brated with cluster stars rather than field stars. The Petrie spectral- type corrections have not been applied in the H-gamma transfers. Both the H-gamma and H-beta indices are apparently affected equally since the systematic difference between the Fernie and Petrie absolute magnitude relations, as mentioned earlier, is preserved in the mean deviations shown in Table 10. Since the observed non-linearity of the photoelectric indices is in the right direction, it is tentatively proposed that the agreement may be purely accidental. The non-linearity of the filters might effectively counterbalance the intrinsically larger equivalent widths (due to lower luminosities) of the cluster stars used in cali bration. The discrepancy between the photoelectric Fernie calibration and the Petrie photographic calibration (with spectral-type corrections) can therefore be explained in a reasonable way. The cluster-star - field- star difference, however, remains to be accounted for in a satisfactory manner. 73
Derived from Photographic Equivalent Widths (Petrie System)
© O-type sts O Other star
“1
Mv Derived from Magnitude Differences• and MK types for Companions
Figure 9 - Correlation Between Absolute Magnitudes Derived in Two Independent Ways for Normal Stars 74 Axial Rotation of Early-type Stars
The rotational velocity results of the present study have been com bined with those of Slettebak (1963. 1966a) and by Boyarchuk and Kopylov
(196^). The combined results have been grouped appropriately to obtain
a set of mean V sin i values and variances. These are listed in Table 11
and shown graphically in Figures 10, 11, and 12. All numbers have been
rounded to the nearest 10 km/sec. The means at type FI were obtained
from the data given by Slettebak (1963).
The new data do not indicate significant differences between single
and double stars provided the physical separation is fairly large. Thus
the conclusion reached previously by Slettebak (1963) remains unchanged.
Similarly, the differences between the rotational velocity means for
stars later than type A3 are not considered to be significant either. For
stars earlier than type A3, the situation is quite different. The means
for the three groups are approximately equidistant with the main-sequence
stars intermediate between the Be stars and classes III and IV. In
particular, the Be stars and classes III and IV show the greatest dis
similarity between means.
The interpretation of these results is difficult because one has to
consider the possible effects of the distribution of sin i as well as
the distribution of equatorial velocity. An additional difficulty is
the fact that the stars are essentially field stars representing a fairly
wide range of ages and so luminosity alone may not be uniquely related
to evolutionary effects. Thus it is not possible to determine how much
of the variance is due to a real dispersion in rotational velocity and
how much is due to inclination effects of incomplete sampling. TABLE 11 - MEAN ROTATIONAL VELOCITIES FOR ALL AVAILABLE STARS WITH MK TYPES
Double Stars Single Stars All Stars < V sin 1> a n
B5-7 V 160 60 17 210 70 30 190 60 47
B8-2 V 170 60 53 150 60 70 160 60 123 A3-7 v 150 50 17 140 60 32 140 60 49 Bl-3 III. IV 120 50 9 100 40 17 110 50 26 B5-7 III, IV 130 50 3 130 50 28 130 50 31 B8-2 III, IV 60 50 3 80 40 20 80 50 23 A3-7 III, IV 160 50 10 170 50 20 170 50 30
Bl-B4e 350 80 7 280 70 41 290 70 48 B5-B7e 320 70 4 300 60 29 300 70 33
B8-A0e 310 60 4 260 60 11 270 60 15
cn MEAN v sin i AGO t ) DOUBLE STARS Q SINGLE STARS 300 Line connecting means for all st; 200
100
0 BO A2 F0 SPECTRAL TYPE Figure 10 - Rotational Velocity Means for Stars of Luminosity Class V
MEAN v sin i (km/sec) 400 0 DOUBLE STARS 0 SINGLE STARS 300 Line connecting mean:: for ail stars 200
100
0 B0 BA Bb A2 At "0 •pi' SPECTRAL TYPE Figure 11 - Rotational Velocity Means For Stars of Luminosity Classes III or IV
LEAN v sin 1 500 IL. (km/sec) G DOUBLE STARS O SINGLE STARS 400 — Line connecting means for* all stars 300
200
100
J. „L 30 3-i 36 A2 A 6 F0 Pi SPECTRAL TYPE Figure 12 - Rotational Velocity Means For Be Stars 77 Stellar Rotation and Absolute Magnitude
The effects of stellar rotation on colors, hydrogen lines, and line ratios have been most recently investigated by Collins (1966), Collins and Harrington (1966) and Collins (1967). These theoretical studies indicate that although individual quantities are influenced by rotation, spectral types and luminosity classes based on line ratios are relatively insensitive to differences in V sin i. It is therefore of interest to see if the observations obtained here indicate any of the predicted effects. Although the Be stars would be ideal test objects because of their high mean rotational velocities, the presence of line abnormalities makes a valid comparison impossible. Thus the objects used in the sample were only the non-emission class V or class IV stars whether primaries or secondary components. a) Effects of Rotation on Balmer-Line Absolute Magnitudes
In the paper by Collins and Harrington (1966), the effects of rota tion on the H-beta index are investigated for a number of rotating con figurations. Collins (1966) has concluded that the apparent displacement of a star in the Mv - (B - V)Q diagram due to rotation depends on 2 9 (V sin i) , not just V as indicated by Strittmatter (1966). Dr. Collins very kindly provided formulae especially for this study for correcting the photoelectric indices for stellar atmospheric and filter effects.
Because line ratio classification is insensitive to rotation (Collins,
1967) the MK spectral type and V sin i for each star could be used to compute the rotationally reddened (B-V) necessary for the correction.
The V sin i for each star was multiplied by a factor of 1.2 before entering it into the correction formulae. This factor is necessary to bring the observed maximum V sin i values for Be stars, which are presumed 78 very nearly equatorial break-up, into agreement with the theoretical break-up velocities upon which the Collins models are based (Collins,
1966; Slettebak, 1966a, 1966b). Various reasons for this discrepancy have been discussed by Slettebak. Regardless of the mechanism, it is considered that all stars are affected to the same degree. Since there is no assurance at this point that this is true, some uncertainty is introduced.
The models used by Collins (1966) indicate that if the zero-age main-sequence is used as a reference, the first-order correlation of difference of and V^sin^i in (km/sec)^ would have the form
MV (ZAMS) - MyCobservational) = A + B (V sin i/100)^ where B is considered to be a constant for regression purposes, although in theory this probably is not true; A is a constant which corrects for zero-point differences. In the statistical analysis presented here, the Mv (ZAMS) chosen was always that corresponding to the MK spectral type.
For the Balmer line correlations, the zero-age main-sequence assumed was that given by Hoag, Johnson et al. (1961). The results of the re gression analysis for the photoelectric and photographic absolute magni tudes are listed in Table 12. The system of calibration is indicated.
For the photoelectric values, correlations using indices corrected by the Collins formulae are indicated by the term "corrected".
The number of stars used varies somewhat because observational errors tended to put some stars outside the region of definition of the mean relations and bring others back in after the Collins corrections were applied. Points were excluded only if their values were outside the range of definition. TABLE 12 - STATISTICAL CORRELATION DATA INVOLVING ABSOLUTE MAGNITUDE AND ROTATIONAL VELOCITIES
Level of Signifi r A A A B aB cance n
1) Photographic H y (Petrie System) O.Qb l.*f 0.1 0.2 0.7 10-* 34
2) He (Fernie System) uncorrected 0.36 0.5 0.1 0.05 0.9 10~2 35 H 1 0 3) H 6 (Fernie System) corrected 0.59 0.5 0.1 0.07 0.9 36
*) Hr (Petrie System) uncorrected 0.67 0.8 0.1 0.09 0.8 10-4 36
5) H y (Petrie System) corrected 0.69 0.3 0.1 0.09 0.9 10-* 38 1 H 0 6) Directly Calibrated M-^s* 0.73 0.9 0.1 0.01 0.7 28 7) Directly Calibrated Mv 's 0.56 0.8 0.1 0.07 0.8 10"3 20
m = MV (ZAMS) - Mv (Balmer) m = A + B(V sin i/100)2 r = mean correlation coefficient n = number of stars
* Includes 0 stars. 80 b) Rotation Effects on the Calibrated Absolute Magnitudes
Regardless of whether rotation affects the Balmer-line absolute- magnitudes or not, it is of interest to see if there is any correlation O of (V sin i) with the calibrated absolute magnitudes. The regression equation assumed and quantities used are exactly as for the Balmer line analysis above. The results, with and without O-type stars, are indicated in the last entries of Table 12.
It should be noted that although the individual slope determinations have rather large probable errors, a mean of all the B values gives
0.08 + 0.03(p.e.). If only the determinations based on corrected photo electric indices are used, a mean of 0.08 + 0.01 (p.e.) is obtained. It is suggested that the probable errors of the individual determinations of the slope are inflated by evolutionary and other effects.
It is also encouraging to note that the Collins corrections improved
the correlation coefficient somewhat in the case of the H-beta indices.
For both photographic and photoelectric H-gamma values, the correlation
coefficients are high, with the Collins correction only producing a minor effect.
On the basis of the available data, rotation-induced effects seem
to be indicated. Until some way of eliminating the rotation effects can be found, accurate age determinations for individual stars relatively near
the ZAMS probably cannot be obtained for spectral types earlier than
about A5.
On The Interpretation of Be Stars
When one attempts to reconcile observations of Be stars with the
astrophysical properties of non-emission stars, the appropriate data
concerning masses and ages are meager. Since the high rotation in these 81 stars generally produces shells and emission structures in their spectra as well as smearing out existing absorption lines, other astrophysical data such as accurate MK classifications and intrinsic colors are difficult to obtain for a sufficient number of objects. It is little wonder, then, that explanations of Be stars are based on little more than conjecture or on small samples.
Although the results of this study suggest several points which have relevance to the Be star problem, much more work is necessary before a satisfactory theory can be proposed. It is of interest to briefly present some comments on several hypotheses concerning Be stars.
Three stages in stellar evolution might be responsible for the Be star phenomenon:
1) Pre-main sequence contraction
2) Main-sequence stage, but rotationally displaced.
3) Post-main sequence-hydrogen exhaustion, core contraction.
Equatorial ejection of material to reduce angular-momentum during the pre- main-sequence contraction phase is certainly a possible explanation for
Be stars, but to date no detailed studies have been carried out. An investigation of rotating stellar models during pre-main-sequence con traction phases is desirable, but this does not seem to be possible at this time because of the complexity of the problem.
The theoretical work by Collins (1966) and Collins and Harrington'
(1966) suggests that Be stars might also be considered to be main-sequence or class IV stars whose exact position in the H-R diagram depends upon
/ stellar angular momentum and the orientation of the observer relative to the rotation axis. During the course of this investigation on double stars, evidence of rotational displacement of non-emission stars was found. Since the Be stars are even more rapidly rotating than the average non emission star, similar effects would be expected. Using the value of B found previously (0.08) and a sample V sin i of about 330 km/sec, one would expect to find these stars as much as 1.1 magnitudes from their zero-rotation luminosity positions. Since the MK calibrations are based on rotating stars with mean V sin i of about 150 km/sec, these will be about 0.7 of a magnitude above the zero-rotation line. Subtracting these
two, one obtains a difference of 0^9 between the Be star absolute magnitude and that for the corresponding non-emission star of the same MK type. A
comparison of the mean deviation of Be star magnitudes obtained from double star calibrations (see Table 10), shows quite good agreement.
Although the agreement might be quite accidental, until this is shown by further observation, the agreement is considered to be tentatively satis factory. It appears therefore that the possibility of rotational dis placement is certainly worth further study for Be stars as well as non emission stars.
In recent papers, both Schild (1966) and Schmidt-Kaler (196^1-) con
cluded that Be stars found in the ^ Persei cluster are the result of
forced rotational ejection during core-contraction phases and apply the
theory of Crampin and Hoyle (i960) to interpret their results. Since many
of the objects described by Schild do not appear to have large rotational
velocities, these may indeed be highly evolved objects. However, a gene
ralization should not be made for all Be stars especially those which are
field stars since:
1) As was pointed out earlier, present stellar evolution computa
tions completely ignore rotation. Even the simple assumption of rigid
rotation is not included. Hence all early-type models should be treated 83 as zero-order approximations to the evolution of rotating configurations.
The situation for break-up is not clear, but is probably worse.
2) The Crampin-Hoyle model does not include accurate model atmosphere calculations.
3) The mode of stellar rotation with depth is completely unknown.
Hence it is impossible to predict at this time how evolution affects the distribution of angular momentum within a star.
Arguments for an evolutionary origin can be found in the previously mentioned papers so they will not be repeated here.
It is evident from the above comments that the interpretation of Be stars is still an open question. Much more work is necessary before any of the hypotheses can be considered to be practical theories. CHAPTER IV
SUMMARY AND CONCLUSIONS
O-type stars
No attempt was made to obtain a two-dimensional spectral classifica tion for these stars. The deviations from the MK calibration do not appear to be systematic for the Am-spectral type (companion) calibra tion. In addition, the spectral type corrections given by Petrie (1965) make the photographic hydrogen-line absolute magnitudes agree well with the MK calibration for O-type stars. However, the same hydrogen-line data
for O-type stars without the spectral type corrections is more consistent with hydrogen line absolute magnitude obtained from photographic equivalent widths to which spectral type corrections have been applied for other early-type stars. This inconsistency suggests that the Petrie system of spectral type corrections should be re-examined.
Rotation Effects in Early-type Stars
The statistical correlation studies described previously indicate 2 2 a positive correlation of "observed" absolute magnitude and V sin i in
such a way that for a given spectral type, the higher the rotation rate
the more luminous the star will appear. The preliminary value for the
slope of the empirical relation indicates that deviations of over one magnitude might be possible for very rapidly rotating stars. It is
therefore considered premature to attempt to discuss the age and subse
quent evolution of individual early-type stars since apparent place on
84 85 the H-R diagram may not be unique 'unless one has a detailed knowledge of the angular momentum distribution on the surface and within each star.
Be Stars
The mean deviation of the -absolute magnitudes of the Be stars from the MK calibration for their spectral type and luminosity class was found to be one full magnitude. Similar results were found for cluster Be stars by Schmidt-Kaler (19&0 and Schild (1966). The discrepancy is consistent with the empirical slope of 0.08 between A m and (V sin i) , a sample mean V sin i for Be stars of 330 km/sec, and a mean V sin i for the MK stars of 150 km/sec. Although provisional, this agreement appears to mean that the hypothesis of rotational displacement must be taken seriously in connection with the problem of Be star over-luminosity.
Rotational Statistics
In accord with the results obtained previously by Slettebak (1963), no significant difference was found between the mean rotational velocities for double stars and those for single stars. The means for the three main luminosity groups Be stars, classes III and IV, and main-sequence for stars earlier than type A2 showed the same trends, but each was separated by about 100 km/sec. After type A2 where there were no emission stars, the luminosity groups were not considered significantly different.
Early-type Giants and Super-giants
Although the Petrie values for these stars showed a large probable error no systematic differences from the MK were found. The MK calibra tion, however, appears to be more than a half magnitude underluminous for
the double stars in the available sample. 86
Recommendations for Further Research
Further study of double stars with components of special interest would, be fruitful. In particular, specific studies of some of the more interesting physical systems mentioned in this thesis are being considered.
Special studies of Be and peculiar stars, especially in relation to the
BO spectral type region of the H-R diagram are needed. Likewise, a re-examination of the rotation statistics as a function of MK type for Be and peculiar stars as well as normal stars should be undertaken. An accurate MK classification of all the stars which have measured rota tional velocities would be immediately useful.
It is felt that the effects of stellar rotation on observable para meters of stars have been underestimated by many investigators. It is only recently that sophisticated theoretical models of stellar structure have had rotation realistically included. However, it is obvious from these studies that the total stellar angular momentum must be known be fore a star can be uniquely described and its future as well as past states specified. An understanding of stellar rotation, in addition to mass, luminosity, and chemical composition, is therefore essential to modern astrophysics. Visual binary star systems provide an opportunity to study these properties in a common sample and should certainly con tinue to be investigated in detail. 87
BIBLIOGRAPHY
Allen, C. ¥. 1963, "Astrophysical Quantities" (London:Athlone Press).
Baize, P. 1962, J. des Observateurs, 4j>, 117.
Bakos, G. A. 1959, A.J., 64, 323.
, and Oke, J. P. 1957, ibid., 62, 242.
Berg, R. A. 1966, Masters Thesis, University of Virginia.
Berger, J. 1962, Ann. d'Ap., 2j>, 1, 77, 184.
Bertaud., C. 1959, U. des Observateurs, 42, 46.
. I960, ibid., 42, 129.
Bidelman, W. P. 1957a, P.A.S.P., 69, 147.
______. 1957b, ibid., 69, 326.
______. 1958, ibid., 70, 168.
______. 1962, A.J., 67, 111.
Blaauw, A. 1963, Chap. 20 of Vol. 3 (Basic Astronomical Data) of "Stars and Systems," ed. G. P. Kuiper (Chicago: Univ. of Chicago Press).
Boyarchuk, A. A., and. Kopylov, I. M. 1964, Pub. Crimea Astrophysical Obs., 21, 44.
Cester, B. 1963, Publ. Obs. Astr. Trieste, No. 319.
Collins, G. ¥., II 1963, Ap. J., 128, 1134.
. 1965, ibid., 142, 265.
______. 1966, ibid., 146, 914.
______., and Harrington, J. P. 1966, ibid., 146, 152.
______. 1967, Paper presented at 124th meeting of the American Astronomi cal Society.
Cowley, A. P., and Cowley, C. R. 1966, P. A. S. P., 78, 165. Crampin, J., and Hoyle, F. I960, M.N., 120, 33.
Crawford, D. L. I960, Ap. J., 132, 66.
Dommanget, J. I960, Bull. Astronomique, 233, 101.
Eggen, 0. J. 1963, A.J., 68, 4-83.
. 1965, ibid., ?0, 19.
Fernie, J. D. 1965, A.J., 70, 575.
Guthrie, B. N. G. 1965. Pub. R. Obs. Edinburgh, _2, 263.
Hardie, R. H. 1962, Chap. 8 of Vol. 2 (Astronomical Techniques) of "Stars and Stellar Systems," ed. G. P. Kuiper (Chicago: Univ. of Chicago Press).
Hertzsprung, E. 1922, B.A.N., 1, 83.
Hiltner, W. A., and Schild, R. E. 1966, Ap. J., 14-3, 770.
Hoag, A. A., Johnson, H. L., Iriarte, B., Mitchell, R. I., Hallam, R., and Sharpless, S. 1961, Pub. U. S. Naval Obs., (2), 17, 349.
Hodge, P. W., and Wallerstein, G. 1966, P.A.S.P., 78, 4-11.
Hopmann, J. 1959» Mitt. Univ. Sternw. Wien, 10, No. 5.
Hynek, J. A. 3.936, Perkins Obs. Conti'., No. 3.0,
Iben, I. 1966, Ap. J., 14^, 483, 505. 516.
Juschek, C., Conde, H., and de Sierra, A. C. 1964, La Plata, Serie Astronomica, 28, (2).
Jaschek, C., Jaschek, M., and Kucewicz, B. 1964, Z.f.Ap., jj>9, 108.
Jeffers, H. M., Van der Bos, W. H., and Greeby, F. M. 1963. Lick Obs. Publ. 20.
Johnson, H. L., and Morgan, W. W. 1953. A.p. J., 117, 313.
. 1953.ibid., 117. 361.
Keenan, P. C. 1963. Chap. 8 of Vol. 3 (Basic Astronomical Data) of "Stars and Stellar Systems," ed. G. P. Kuiper (Chicago: Univ. of Chicago Press).
Kelsall, T., 1965. (See Stromgren).
Koch, R. H., Sobieski, S., and Wood, F. G. 1963, A Finding List for Eclipsing Variables, Publ. Univ. of Penn. (Astr.), 2.
Koritnikov, S. N., Laurov, M. I., and Martinov, D. Y. I96I-I963, Bibliography of Spectroscopic Binaries, Moscow. 89
Kuhi, L. V. 1966, Ap.J., 143, 753-
Kukarkin, B. W . , Parenago, P. P., Efremov, J. I., and Kholopov, P. N. 1959-1964, General Catalogue of Variable Stars, with Supplements, Moscow.
Leonard, F. C. 1923, L.O.B., 10, 169 (No. 343).
Lundmark, K., and Luyten, W. J. 1923, A.J., 35.
Luyten, W. J. 1957, J.R.A.S.C., 51, 41.
McLaughlin, D. B. 1961, A.J., 66, 48.
______. 1951, ibid., 56, 48.
McNally, D. 1965, The Observatory, 85, 166.
Merrill, P. ¥., and Burwell, C. G. 1933, Ap.J., 78.
______.,______. 1943, ibid*. 98, 153.
.,______. 1949, ibid., 110, 387.
Moore, J. H., and Neubauer, F. J. 1948, L.O.B., 20, 1.
. 1936, ibid., 18, 1.
Morgan, W. W., Code, A. D., and Whitford, A. E. 1955, Ap.J. Suppl., 2, 41.
Morgan, W. W., Keenan, P. C., and Kellman, E. 1943, An Atlas of Stellar Spectra, Univ. of Chicago.
Opolosky, A. 1956, Arkiv.f.Astr., 2, No. 6.
Osawa, K. 1959, Ap.J., 130, 159.
Perova, N. 1964, Peremenya Svezd, 14, No. 5, 113*
Petrie, R. M. 1965, Pub. Dom. Ap. Obs., 12, No. 9.
______., and Batten, A. H. 1966, Trans. I.A.U., Vol. XIIB, 476.
Plaut, L. 1934, B.A.N., 7, 181.
., 1939, ibid., 9, 49.
Roberts, M. 1962, A.J., 67, 79*
Roman, N. 1955, Ap.J. Supp., 2, No. 18.
. 1951, Ap.J., n 4 , 492. 90
Roxburgh, I. W . , and Strittmatter, P. A. 196>5» Z.f.Ap., 6^3, 15.
Schild, R. E. 1965, Ap.J., 142, 979.
. 1966, ibid., 146, 142.
Schmidt-Kaler, Th. 1964, Z.f.Ap., 58, 217.
Slettebak, A. 1949, Ap.J., 110, 498.
. 1954, ibid., 119, 146.
. 1955, ibid., 121, 653.
. 1956, ibid., 124, 173.
______., and Howard, R. F. 1955, ibid., 121, 102.
. 1963, ibid., 138, 118.
. 1966a, ibid., 145, 121.
. 1966b, ibid., I4j3, 126.
Stephenson, C. B. i960, A.J., 65, 60.
______. 1965, Ap.J., 142, 309.
Stothers, R. 1966, Ap.J., 143, 91.
Stromgren, B. 1965, Chap. 4 of Vol. 8 (Stellar Structure) of "Stars and Stellar Systems," ed. G. P. Kuiper (Chicago: Univ. of Chicago Press).
Struve, 0., and Franklin, K. L. 1955, Ap.J., 121, 337.
.,______., and Stableford, R. 1955, Ap.J., 121, 670.
Sweet, P. A., and Roy, A. E. 1953, M.N., 1T3, 701.
Tolbert, C. R. 1964, Ap.J., 3JS9, 1105.
Tchudovitch, V. P. 1961, Bull. Engelhardt Obs. Kasan, 28.
Tilley, E. C. 1943, Ap.J., 98, 347.
Wallenquist, A. 1954, Ann. Uppsala Astr. Obs., 4, No. 2.
-______. 1958, Medd. Astr. Obs. Upp. No. 118.
Wallerstein, G., and Westfall, J. I960, A.J., 65, 323.
Weaver, H., and Ebert, A. 1964, P.A.S.P., 76, 6. Wilson, R. E. 19^1, Ap. J., 92, 212.
______. 1953, General Catalogue of RadialVelocities, Carnegie Inst. Wash., D.C.
Wood, H.J. 1965» Publ. Leander McCormick Obs. ljj, pt.II, 5»
Worley, C. 1963, Publ. U. S. Naval Obs. 18.