The first ideas for the symposium were generated in Brussels in the summer of 1986, dur- ing exquisite lunches in between HST proposal consortium meetings. At the time it was expected that soon after the previous IAU symposium (No. 116) devoted to luminous hot massive stars, a bonanza of new exciting observational material would become available, together with significant advances on the theoretical front. Also it was felt that Wolf- Rayet stars should feature predominantly, because that had not been the case since IAU Symposium No. 99 in 1981. Tradition requires that IAU symposia on hot...

The first ideas for the symposium were generated in Brussels in the summer of 1986, dur- ing exquisite lunches in between HST proposal consortium meetings. At the time it was expected that soon after the previous IAU symposium (No. 116) devoted to luminous hot massive stars, a bonanza of new exciting observational material would become available, together with significant advances on the theoretical front. Also it was felt that Wolf- Rayet stars should feature predominantly, because that had not been the case since IAU Symposium No. 99 in 1981. Tradition requires that IAU symposia on hot...

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...