Proceedings of the 99th Colloquium of the International Astronomical Union, held in Balaton, Hungary, June 22-27, 1987

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...

"An atteJDpt has been made to cOll1PlJte the numbers of certain JI10lecules in interstellar space , ...A search for the bands of CH, O/{, DR, en and C2 would appear to be proIDising" P Swings and L Rosenfeld Astrophysical Journal 86,483(1937) This may have been the first attempt at modelling interstellar chemistry. As with models today, the methods used lacked reliability, but the speculation was impressive! Mark Twain might well have said of this infant subject "One gets such wholesale returns of conjecture out of such a trifling investment of fact". The detection of unidentified lines...

The millimetre and submillimetre spectral region (300 to 3000 Ilm or 1000 to 100 GHz) was until recently one of the few spectral regimes not fully opened up for astronomical studies. Thanks both to improvements in detectors and receivers and to the construction of large telescopes at high altitude sites this situation is improving very rapidly. Three major telescopes have been built recently and are coming into operation during 1987 and 1988, namely the 15m James Clerk Maxwell Telescope (JCMT) and the lOAm Caltech Submillimetre Observatory (CSO) telescope, both located on Mauna Kea, Hawaii,...

Stellar mass loss is an essential part of the cycling of material from the interstellar medium into stars and back, and must be understood if we are to model processes on galactic to cosmological scales. The study of stellar winds and the effects of stellar mass loss has reached a particularly exciting stage where observational capabilities are increasingly able to provide interesting constraints on models and theories. Recent resu1ts from theoretical and observational work for both hot and cool stars with substantial winds have led to the suggestion that a combination of pulsation with other...

Over the last decade we have witnessed a rapid change in our understanding of the late stages of stellar evolution. A major stimulus to this has been the synthesis of observational data from different wavebands of the electromagnetic spectrum. The advent of infrared astronomy has led to the discovery of many luminous. late-type stars obscured by their circumstellar dust envelope. Sources discovered in the IRC and AFGL infrared sky surveys were followed up by radio observa- tions, leading to the widespread use of the OH and CO molecules as probes of the circumstellar envelopes. Advances in the...

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...

On April 28 1986 Cornelis de Jager reached the age of 65 years. On April 30 he officially retired from the University of Utrecht where he has held a Chair for Stellar Astrophysics, later changed into Space Physics, since 1958. Cees de Jager, as he prefers to be called by his friends, has had an active and successful life in science. His interest in astronomy was raised by his father under the clear skies of Celebes (Indonesia). He started a study in physics and astronomy as a student of the late M. Minnaert in Utrecht during World War II. When in 1943 the occupying forces recruited students...

It is clear that the discovery of solar eigenmodes and the resulting possibility of probing the solar interior is an event of primary importance for solar physics in general and for theories of the inner solar angular velocity in particular. While these theories are basic for the understanding of the solar spin down, differential rotation, dynamo and activity, they are however, extremely complex, and in all likelihood only limited further progress could have been achieved without the guidance of observations. Until recently and in spite of the scant observational basis the theoretical work...

As it was said by one of the participants to this workshop" In our attempts to understand the spectral evolution of galaxies, we are fortunate indeed to have the ability to look back in time and observe galaxies as they were billions of years ago. Perhaos in no other discipline is it possible to gain such a direct view to hJstory. The galaxies we seek to study are remote, their light faint, and thus only recently has it become technicaJlv feasible to sample the spectra of normal luminosity galaxies at lookback times of five billion years or more" ...or, perhaps. even to see galaxies in the...