The Nature of Symbiotic Stars : Proceedings of IAU Colloquium No. 70 Held at the Observatoire De Haute Provence, 26–28 August, 1981

Many aspects of symbiotic stars have long puzzled astronomers. For instance while most students of the subject have considered them binary, many have at different times supported single star models. The nature of their outbursts is uncertain, while the dividing line between symbiotic stars and novae is unclear. In any case doubts can even be raised as to whether a class of "Symbiotic Stars" really exists. Much new data has been obtained in recent years, in particular from the study of radiation outside the visual region. Many symbiotic stars have been studied in the UV with IUE since 1978, while X-rays were det­ ected in a few cases with the Einstein satellite. There have been a num­ ber of infrared and radio studies, and the number of known symbiotic stars has also considerably increased. Furthermore theoretical ideas have in recent years been considerably enriched by concepts of stellar winds, and accretion phenomena in binaries including accretion disks. It was there­ fore extremely opportune and timely to hold the first international meet­ ing exclusively devoted to these stars, so as to consider the new results from such a wide range of observations in different spectral regions, and the conclusions which can be drawn for possible models as well as theories of the nature and structure of symbiotic stars. After a session devoted to new observations in different spectral regions, a session was spent considering some individual stars. Front Matter....Pages i-xix Front Matter....Pages 1-1 Fifty Years of Symbiotic Stars....Pages 1-9 Introductory Report on Symbiotic Stars....Pages 11-14 Front Matter....Pages 15-15 Radio Observations of Symbiotic Stars....Pages 17-26 Infrared Studies of Symbiotic Stars....Pages 27-42 IR Photometry of Symbiotic Stars at Calar Alto Observatory....Pages 43-45 Near IR Spectra of Symbiotic Stars....Pages 47-56 Photographic Infrared Spectra of Symbiotic Stars....Pages 57-60 Properties of Symbiotic Stars from Studies in the Optical Region....Pages 61-70 Spectra of Individual Symbiotic Stars....Pages 71-82 Visual Symbiotic Spectra Obtained with the Haute Provence Multiphot Detector....Pages 83-84 UV Line Emission of Symbiotic Stars....Pages 85-102 Ultraviolet Properties of the Symbiotic Stars....Pages 103-113 X-Ray Observations of Symbiotic Stars....Pages 115-116 X-Ray Detection of the Symbiotic Star AG Draconis....Pages 117-121 Front Matter....Pages 123-124 Z Andromedae: The Prototype?....Pages 125-130 A Review of the Properties of the Symbiotic Star CH Cygni....Pages 131-136 Recent Increase of the Activity of the Symbiotic Star CH Cygni....Pages 137-138 Polarimetry of CH Cygni....Pages 139-140 UV Eclipse Observations of CI Cyg....Pages 141-144 IUE Observations of CI Cygni during 1979–1981....Pages 145-146 Front Matter....Pages 123-124 The Eclipse of CI Cygni in 1980 on the Objective Prism Spectra....Pages 147-148 Variation Spectrale DE CI Cyg EN 1975....Pages 149-150 Spectral Variations of CI Cyg between 1980 and 1981....Pages 151-152 Optical Observations of CI Cygni....Pages 153-156 Introductory Report on V1016 Cygni....Pages 157-160 Recent Studies of the Spectrum of V1016 Cygni....Pages 161-163 The Peculiar Symbiotic Object V1329 Cygni: Single-Star Versus Binary Models....Pages 165-168 Physical Properties of V1329 Cygni....Pages 169-171 Variability of HBV 475 in the near Infrared....Pages 173-174 Spectral Evolution of HBV 475 (= V1329 Cygni) in the Ultraviolet....Pages 175-176 Introductory Remarks on the Symbiotic Star AG Draconis....Pages 177-181 The Ultraviolet Spectrum of AG Draconis....Pages 183-184 Spectroscopic Observations of AG Dra....Pages 185-189 UV Time-Dependent Emission in SY Muscae....Pages 191-194 AR Pavonis: The Rosetta Stone of the Symbiotics....Pages 195-200 Introductory Report on AG Pegasi....Pages 201-202 The Peculiar Star RX Puppis....Pages 203-206 Long Term Trends in the 3.5μ Light Curve of RX Puppis....Pages 207-208 HM Sagittae — A most Remarkable Star....Pages 209-211 Spectral Evolution of HM Sagittae in the Ultraviolet....Pages 213-214 Front Matter....Pages 123-124 RR Telescopii....Pages 215-216 Ultraviolet Observations of RR Telescopii....Pages 217-218 V 4049 Sgr....Pages 219-220 The Kuwano Peculiar Object (PU Vulpeculae)....Pages 221-222 Front Matter....Pages 223-223 Determination of the Term Symbiotic Star....Pages 225-230 The Symbiotics as Binary Stars....Pages 231-251 Models for Symbiotic Stars in the Light of the Data....Pages 253-267 Symbiotic Star UV Emission and Theoretical Models....Pages 269-272 Front Matter....Pages 273-273 The Evolutionary Status of Symbiotic Stars....Pages 275-282 On the Model of Symbiotic Stars....Pages 283-296 Concluding Remarks....Pages 297-302 Back Matter....Pages 303-314