INFORMATION TO USERS The most advanced technology has been used to photograph and reproduce this manuscript from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. University Microfilms International A Bell & Howell Information Company 300 North Z eeb Road, Ann Arbor, Ml 48106-1346 USA 313/761-4700 800/521-0600 Order Number 9031106 A spectroscopic investigation of dwarf novae during the early rise of outburst Mansperger, Cathy Sue, Ph.D. The Ohio State University, 1990 Copyright ©1990 by Mansperger, Cathy Sue. All rights reserved. UMI 300 N. Zeeb Rd. Ann Aibor, MI 48106 A SPECTROSCOPIC INVESTIGATION OF DWARF NOVAE DURING THE EARLY RISE OF OUTBURST DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University By Cathy Sue Mansperger, B.S.P.A., M.S. * * * * * The Ohio State University 1990 Dissertation Committee: Approved by R.H. Kaitchuck A.E. Slettebak R.F. Wing Adviser G.H. Newsom Department of Astronomy Copyright by Cathy Sue Mansperger 1990 ACKNOWLEDGMENTS I would like to thank Arne E. Slettebak, Robert F. Wing, and Gerald H. Newsom for serving on my committee, and for their comments and helpful suggestions. I would also like to thank George W. Collins II for helping me find a job. Appreciation goes to John Cannizzo for his useful comments and for directing me to Mineshige's paper. I acknowledge the AAVSO visual data sent by the Director, Janet A. Mattei. I would also like to express my gratitude to Gerald Dyck and Elizabeth 0. Waagen for the aid they gave me during the observing runs which allowed me to catch these dwarf novae during the preoutburst stage. I would especially like to thank Ronald H. Kaitchuck, not only for his invaluable assistance with the research throughout this study, but for his moral support and patient guidance during the past five years. il VITA January 16, 1962 ............... Born - Columbus, Ohio 1984 ............................ B.S.P.A., The University of Georgia, Athens, Georgia 1984-1985........................ Research Assistant, Space Telescope Science Institute, Baltimore, Maryland 1985-1986........................ Teaching Associate, The Ohio State University, Columbus, Ohio Summer, 1986 .................... Research Associate, The Ohio State University, Columbus, Ohio 1986-1987........................ Teaching Associate, The Ohio State University, Columbus, Ohio Summer, 1987 .................... Research Associate, The Ohio State University, Columbus, Ohio 1987 ............................ M.S., The Ohio State University, Columbus, Ohio 1987-Present .................... Head Teaching Associate, The Ohio State University, Columbus, Ohio PUBLICATIONS Mansperger,C.S.1987, "Spectroscopy of the Dwarf Nova RX And in Outburst and Quiescence", M.S. thesis,The Ohio State University. Kaitchuck,R.H.,Mansperger,C.S.,and Hantzios,P.A.1988, "Spectroscopy of the Dwarf Nova RX Andromedae from Quiescence to Eruption", Astrophysical Journal,330,305. iii Scott,J., Mansperger,C.,Brainerd,T.,and Saizar,P.1988, Sample Examination Questions for Introductory Astronomy Courses, 2nd ed. (Edina, MN: Burgess International). Mansperger,C.S.,and Kaitchuck,R.H.1990, "Spectroscopy of the Dwarf Nova TW Virginis Caught on the Rise to Outburst", Astrophysical Journal,in press. FIELDS OF STUDY Major Field: Astronomy Studies in Cataclysmic Variables with Dr. R. H. Kaitchuck. iv TABLE OF CONTENTS ACKNOWLEDGMENTS.................... ii VITA ....................................................... iii LIST OF TA B L E S ............................................. vii LIST OF FI G U R E S ........................................... viii CHAPTER PAGE I. INTRODUCTION ....................................... 1 II. OBSERVATIONS....................................... 20 RX A n d .................................. 25 SS C y g ............................................ 36 KT P e r .................................... 40 AH H e r ............................................ 45 AR A n d ............................................ 50 TW V i r ............................................ 53 Summary of Preoutburst Behavior .................. 58 III. COMPARISON WITH OTHER OBSERVATIONS ................. 61 Quiescence........................................ 63 Rise to M a x i m u m .................................. 65 M a x i m u m .......................................... 65 D e c l i n e .......................................... 67 IV. DISCUSSION OF PREOUTBURST STAGE .................. 69 RX And: 1985 December............................ 69 RX And: 1987 Oc t o b e r ............................ 70 SS Cyg: 1987 Ju n e ................................ 70 KT Per: 1988 Se p t e m b e r .......................... 71 AH Her: 1988 Se p t e m b e r .......................... 71 AR And: 1988 Se p t e m b e r .......................... 72 TW Vir: 1988 Se p t e m b e r .......................... 72 S u m m a r y .......................................... 72 V. COMPARISON WITH T H E O R Y ............................. 81 v CHAPTER VI . CONCLUSIONS BIBLIOGRAPHY LIST OF TABLES TABLE PAGE 1. Physical Data for Program S t a r s ................... 22 2. Observational Data for Program S t a r s ............... '23 3. Observed Spectral Changes During the Preoutburst S t a g e ........................................... 58 4. Outburst Coverage of Dwarf Novae ................... 64 5. Model Line Emitting Regions During Preoutburst . 78 6. Final Model Parameters for TW Vir, Black Body M o d e l ........................................... 87 7. Final Model Parameters for TW Vir, Stellar Atmospheres Model ............................... 90 8. Final Model Parameters for RX And, Stellar Atmospheres Model ............................... 100 vii LIST OF FIGURES FIGURE PAGE 1. Light curve of the dwarf nova SS Cyg based on AAVSO visual observations. For a complete AAVSO light curve from 1896-1985 see Mattei et al. (1985)............................................. 10 2. The surface density (E) vs Temperature (T) relationship from Smak (1984a).................... 13 3. IDS light curve for the 1985 December RX And outburst........................................... 26 4. The AAVSO light curve for RX And during the 1985 December outburst. The horizontal lines along the bottom of the plot indicate the times of the IDS spectroscopic observations......................... 27 5. Equivalent width of H-beta emission versus UT for RX And on 1985 December 15 (left), and 1985 December 16 (right)......................................... 28 6. Gray-scale image of RX And on 1985 December 15 (top) and 1985 December 16 (bottom) scaled to show the extreme emission line wings. Orbital phase runs down the image. Note the narrowing of the H-beta line from phase 0.6 to phase 0.84. He II 4686 may also have narrowed................................. 30 7. Gray-scale images of RX And for 1985 December 18 (top) and 1985 December 19 (bottom). Note the apparent splitting of the H-beta emission line between the phase 0.7 and 0.2. On the 19th the H-beta emission line seems to have a two-component structure.......................................... 31 8. Approximate B mag vs UT for RX And on 1987 October 16 (left) and 1987 October 18 (right). ......... 32 viii FIGURE PAGE 9. Line flux of the H-beta emission line vs UT for RX And on 1987 October 16 (left) and 1987 October 18 (right)............................................ 33 10. Mean spectra of RX And on 1987 October 16 and 18............................................. 34 11. FWHM of the H-beta emission vs UT for RX And on 1987 October 16 (right) and 1987 October 18 (left)............................................. 35 12. Mean spectra of SS Cyg on 1987 June 18-19.......... 37 13. Mean spectra of SS Cyg on 1987 June 20-22.......... 38 14. Line flux (top) and FWHM (bottom) of H-beta emission of SS Cyg. Data set 1 is the averaged data from 1985 August and September. Data set 2 is the averaged data for 1987 June 18, and data set 3 is the averaged data for 1987 June 19..................................... 39 15. IDS light curve of KT Per on 1988 September 15-23....................................... 41 16. Mean spectra of KT Per on 1988 September 15-17. The spectrum for the 16th is represented by a dotted line to distinguish