Bücher der Reihe International Astronomical Union Symposia

Proceedings of the 147th Symposium of the International Astronomical Union, held in Grenoble, France, June 12-16, 1990

Proceedings of the 149th Symposium of the International Astronomical Union, held in Angro dos Reiz, Brazil, August 5-9, 1991

Proceedings of the 153rd Symposium of the International Astronomical Union held in Ghent, Belgium, August 17--22, 1992

Proceedings of the 155th Symposium of the International Astronomical Union held in Innsbruck, Austria, July 13--17, 1992

In this Symposium, researchers specializing in pulsation, rotation, magnetic fields and stellar winds are brought together for the first time in order to broaden our understanding of O and B stars. The variability of radiatively-driven winds from O and B stars are likely related to the rotation of the star.

Proceedings of the 171st Symposium of the International Astronomical Union, held in Heidelberg, Germany, June 26-30, 1995

Proceedings of the 188th Symposium of the International Astronomical Union, held in Kyoto, Japan, August 26-30, 1997

Proceedings of IAU Symposium No. 70 (Merrill-McLaughlin Memorial Symposium) held at Bass River, Massachusetts, U.S.A., September 15-18, 1975

Proceedings of the 146th Symposium of the International Astronomical Union, held in Paris, France, June 4-9, 1990

Proceedings of IAU Symposium No. 95 held in Bonn, Federal Republic of Germany, 26-29 August 1980

Proceedings of the 85th Symposium on the International Astronomical Union held in Victoria, B.C., Canada, August 27-30, 1979

"If simple perfect laws uniquely rule the universe, should not pure thought be capable of uncovering this perfect set of laws without having to lean on the crutches of tediously assembled observations? True, the laws to be discovered may be perfect, but the human brain is not. Left on its own, it is prone to stray, as many past examples sadly prove. In fact, we have missed few chances to err until new data freshly gleaned from nature set us right again for the next steps. Thus pillars rather than crutches are the observations on which we base our theories; and for the theory of stellar evolution these pillars must be there before we can get far on the right track. " These words written by Martin Schwarzschi1d in his famous book en­ titled "Structure and Evolution of the Stars"(1958) remind us how necessary and fruitful is the interplay of stellar evolution theory and observations. Clearly, observations are the great censor by their possibility of confirming or contradicting theoretical constructions. In addition, they have a driving role: new and sometimes unexpected facts may give rise to progressive ideas and stimulate further theoretical developments. In turn, theory, in its major role of sifting out and placing the facts in a logical sequence based on physical laws, must also be predictive and indicate new and pertinent observations to be undertaken.

This book contains the proceedings of IAU Symposium No. 151 `Evolutionary Processes in Interacting Binary Stars,' which was held from 5 to 9 August 1991 in Cordóba, Argentina. The primary aim of this conference was to review and evaluate our current understanding of the evolutionary processes in wide variety of interacting binary stars from their births to their deaths. Subjects included the formation of binaries, mass flow and transfer, accretion processes, and binaries with collapsed components, such as novae, X-ray binaries and binary pulsars. As the field covered is both broad and diverse, there were in all thirty-seven invited talks; sixty-two contributed papers were also presented. In addition, these proceedings contain comments from a panel discussion of the major unsolved problems of interacting binary stars.

Proceedings of IAU Symposium No. 41, held in München, Germany, August 10-14, 1970

Much of the excitement in modern Solar Physics has come from the realisation that the Sun is a plasma and that this plasma is interacting with the magnetic field in a wide variety of subtle ways. As well as being of great interest in their own right the observed plasma phenomena on the Sun are of much wider importance, since they reveal to us details of basic phenomena that are expected to be occurring throughout the universe. It was with this in mind that 173 solar physicists from 17 countries gathered together in Bangalore with an air of anticipation. We were not disappointed as we received the warmest of welcomes from our graceful and charming host,Vinod Krishan. She and her colleagues worked tirelessly to make our stay a most memorable one and to ensure that the meeting ran with calm and efficiency. In addition to being stimulated by an excellent series of talks on the up-to-the­ minute advances in our subject, it was a pleasure to make new friendships from so many countries and to learn, in particular, of the Solar Physics being done in India which has a great tradition and is of a high standard. Furthermore, we enjoyed hearing about Indian culture and appreciating its beauty, especially on our day's tour into the countryside to visit some Hindu and Jain temples.

G. MICHAUD Dipartement de Physique Universiti de Montrial c. P. 6128, succursale A Montrial, Que. , H3C 317 Canada The aim of IAU Symposium 145 was to use the photospheric abundances of the chemical elements to give us some hint of the past evolution and of the current structure of stars. At the invitation on the Bulgarian Academy o/Sciences, it brought together one hundred and fifty one scientists from 21 countries to 71atni Pjasaci (Golden Sands), Bulgaria, for a five day meeting. The processes discussed included accretion, mass loss, mass exchange, convection, turbulence, meridional circulation, and diffusion in addition to nuclear reactions. Observationally, spectroscopy was involved. New telescopes and instruments have considerably extended the scope of spectroscopy over the last few years. Space telescopes, such as IUE, have allowed the development of far UV spectroscopy. The access to the infrared has proven critical for probing cool stars. Large ground based telescopes have allowed fainter objects to be observed especially when they are equipped with more efficient detectors such as CCDs and Reticons. The co-adding of digitalized photographic plates has extended their usefulness. It has become possible to make high resolution, high signal to noise observations of objects that could only be observed at low resolution in former days. Weak lines can now be measured with accuracy, allowing the precise determination of the abundances of elements as rare as lithium and the determination of precise limits to isotopic ratios.