This book represents the proceedings of a NATO Advanced Study Institute which was held at Bonas from August 25 till Sep tember 5, 1980 and was devoted to the study of "Solar Phenomena in Stars and Stellar Systems". It is intended for a broad audi ence. Students and post-doctoral scientists for example can dis cover new aspects of astrophysics. The general spirit of the ASI was aimed at presenting a unified aspect of astrophysical phenomena which can be studied intensively on the Sun although they are of a much more general nature. On the other hand, spe cialists in solar or stellar physics will find here the latest theoretical developments and/or the most recent observations made in their own field of research. An extensive bibliography will be found throughout the various sections, to which the reader may refer, for more detailed developments in various specific areas. In the past, stellar and solar astrophysics have more or less followed their own independent tracks. However, with the rapid development of modern techniques, in particular artificial satellites like the International Ultraviolet Explorer and the Einstein Observatory, which provide a new wealth of data, it appears that chromospheres, coronae, magnetic fields, mass loss and stellar winds, etc . . . . , are found not only in the Sun but occur also in other stars. Frequently these other stars represent quite different conditions of gravity, lumino~ity, and other parameters from those occurring in the Sun.

Proceedings of the NATO Advanced Study Institute, Bonas, France, August 25-September 5, 1980

Inhalt
I. General Overview.- The Sun as a Star: Solar Phenomena and Stellar Applications.- The Spontaneous Concentration of Magnetic Field in the Photosphere of the Sun.- II. Interiors.- Internal Structure of the Sun and Stars.- Solar and Stellar Oscillations.- III. Chromospheres/Coronae and Convective Phenomena.- Evidence for Chromospheres and Coronae in Stars: Recent Observations, Some Unanswered Theoretical Questions, and a Speculative Scenario.- Convection Zones in Sun and Stars.- Results from the Central Hyades Survey.- Compressible Convection in a Rotating Spherical Shell.- Energy Balance in Solar and Stellar Chromospheres.- Energy Balance in Solar and Stellar Coronae.- Numerical Studies of the Energy Balance in Coronal Loops.- Energy, Balance and Armagnac.- Theories of Heating of Solar and Stellar Chromospheres.- Mechanical Flux in the Solar Chromosphere.- Magnetic Heating in the Sun.- Magnetohydrodynamics of Thin Flux Tubes.- Coronal Holes and Solar Mass Loss.- The Solar Wind: Macroscopic Features and Microscopic Problems.- Observations and Theory of Mass Loss in Late-type Stars.- IV. Solar and Stellar Variability.- Aspects of Long-term Variability in Sun and Stars.- The Solar Neutrino Problem.- Chromospheres and Coronae in Binary Systems.- The RS Canum Venaticorum Binaries.- Stellar Magnetic Structure and Activity (Theory).- Stellar Magnetic Structure and Activity.- Stellar Spots Physical Implications.- Photospheric Magnetic Field Patterns and Their Coronal and Interplanetary Consequences.- Solar Flares: Magnetohydrodynamic Instabilities.- Diffuse Reconnection: The Resistive Tearing-mode.- Stellar Analogs of Solar Microwave Phenomena.- V. Conclusion.- Summary Commentary.- Index of Names.- Index of Subjects.