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.
Symbiotic stars were identified spectroscopically as M giants with a very strong He II 4686 emission line. After five decades of study by many astronomers, the first internatioinal meetings devoted to symbiotics were held at the University of Colorado (Boulder) and at the Haute Provence Observatory during the Summer of 1981. These conferences emphasized exciting new results obtained by modern satellite (EINSTEIN, IUE) and ground-based observatories. Although the vast majority of the participants were already fairly sure that symbiotics are almost certainly interacting binary systems, and not extremely peculiar single stars, it was not clear exactly which types of physical processes were needed to be invoked to explain their observed behaviour. Many were even worried that it might not be possible to clearly define a class of "symbiotic stars" , and thus establish a unique model applicable to any system. Since the publication of the Haute-Provence proceedings, our understanding of the physical processes occuring in symbiotic stars (and in related objects such as cataclysmic variables and compact planetary nebulae) has greatly improved. We now speak confidently of a "symbiotic phenomenon" , in which an evolved red giant and a hot companion object (usually thought to be an accreting main sequence star or a luminous white dwarf star) happily coexist.
Dr Kenyon has researched and assembled here all the existing data for the known symbiotic stars, in which a dwarf star accretes material from its red giant companion. In this book he summarises observational material covering the eruptive and quiescent phases of these objects, and emphasises the important astrophysical problems raised and resolved by results at infrared, optical, radio, ultraviolet and X-ray wavelengths. Physical models for the eruptive and quiescent phases and the long-term evolution of symbiotic stars are discussed, with the goal of developing observational diagnostics that serve to test the basic theories. The book concludes with a detailed appendix and bibliography that will aid researchers interested in the history of individual symbiotic systems and confirm this volume as an indispensable handbook at any observatory where research on stellar objects in undertaken.
Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied meticulously by scientists. Astronomers, astrophysicists, physicists, researchers, and students in related fields will find the book interesting.
This volume begins with an introductory chapter on general properties of cataclysmic variables. Chapters 2 through 5 of Part 1 are devoted to observations and interpretation of dwarf novae and nova-like stars. Chapters 6 through 10, Part 2, discuss the general observational properties of classical and recurrent novae, the theoretical models, and the characteristics and models for some well observed classical novae and recurrent novae. Chapters 11 through 14 of Part 3 are devoted to an overview of the observations of symbiotic stars, to a description of the various models proposed for explaining the symbiotic phenomenon, and to a discussion of a few selected objects, respectively. Chapter 15 briefly examines the many unsolved problems posed by the observations of the different classes of cataclysmic variables and symbiotic stars.
The Bosscha Observatory in Lembang, Java, Indonesia, celebrated in 1983 its 60th anniversary. Since its foundation, the physical properties of binary systems have formed a major research topic of this observatory. Until 1970, the study of visual binaries and the determination of orbits received most emphasis. Since then, also the evolution of close binary systems, such as X-ray binaries, Wolf-Rayet binaries and binary pulsars, has been researched with priority in Lembang. It seemed thus appropriate that a Colloquium devoted to the study of binary systems be held in Lembang at the time of the Observatory's anniversary. In the Colloquium, the role of wide double (and multiple) systems received special emphasis - not only because of the long tradition of visual binary research at Lembang; but also because their role in documenting stellar evolution has been largely overlooked in recent decades, and needs to be brought into focus with the information forthcoming from close binaries. The Colloquium covered the physical properties of visual as well as close binary systems, and their generic relations, in the broadest possible sense. It was sponsored by the International Astronomical Union as IAU Colloquium No. 80 ('Double Stars, Physical Properties and Generic Relations'). After the official opening ceremony, the meeting started with a discussion on the future of astronomy in Asia. The scientific sessions began with the 'V. Bappu Memorial Lecture on the Evolution of Binary Systems', presented by Z. Kopal.
There are two questions that we can ask ourselves in order to describe this workshop. The first question is a double question: why a conference on this subject and why a workshop? The first idea of organizing this workshop came while reading the scientific objectives of one of the instruments onboard the ISO satel lite (a phase A document concerning the IR camera). On going through the scientific motivations for building the instrument I realized with surprise that no mention was made of Planetary Nebulae (PN). At present this is no longer true. There is a chapter indicating the capabilities of the camera in the PN field and what we can reasonably expect from that instrument. But it was at this moment that the first idea of organizing a workshop on the subject of PN came. Of course there are other, stronger motivations. The first one is that I think this is the right moment after IRAS. I think we all spent the last two or three years working on IRAS data. IRAS represented a corner-stone for those working on Planetary Nebulae: the amount of data that came out of the instruments onboard the satellite was enormous and opened up new ways of looking at planetary nebulae, as well as at other fields.
Emission line stars are attractive to many people because of their spectacular phenomena and their amazing varieties and variability. This book offers general information on emission line stars, starting from a brief introduction to stellar astrophysics and then moving to a broad overview of emission line stars including early and late type stars as well as pre-main sequence stars.
This is the first non-technical book on spectroscopy written specifically for practical amateur astronomers. It includes all the science necessary for a qualitative understanding of stellar spectra, but avoids a mathematical treatment which would alienate many of its intended readers. Any amateur astronomer who carries out observational spectroscopy and who wants a non-technical account of the physical processes which determine the intensity and profile morphology of lines in stellar spectra will find this is the only book written specially for them. It is an ideal companion to existing books on observational amateur astronomical spectroscopy.
This written account of the Symposium on Planetary Nebulae was prepared from manuscripts submitted by the participants. Nearly every paper that was presented at the meeting is reproduced here, in either complete or abbreviated form. The dis cussions have been somewhat shortened and rearranged, but we have tried to preserve the essential points and the general tenor of the exchanges. Participants who spoke in the discussion were asked immediately for written remarks, which were then edited, reproduced, and circulated at the meeting by the highly effective local Secretariat organized by Dr Perek. In addition, notes of the discussion taken by Mrs Edith F. Swan and by the undersigned were used. We wish to thank all the authors for their unusually good cooperation. We are especially grateful to Dr Minkowski, who kindly provided many excellent repro ductions of Mount Wilson and Palomar photographs, mostly taken by himself, of various planetary nebulae. We are particularly indebted to Mrs Swan, who attended the Symposium, made notes on the papers and discussions as they occurred, and did much of the checking and editing of the manuscripts. In addition, we are very grateful to Mrs Evelyn Seaver, who also did much of the checking, editing, and retyping of manuscripts, and to Dr B.L. Webster, Miss Rebecca Todd, Mr Joseph Tapscott, and Mr Dennis Schatz, who provided excellent assistance in the preparation of this volume.