This symposium was devoted to a new celestial mechanics whose aim has become the study of such objects' as the planetary system, planetary rings, the asteroidal belt, meteor swarms, satellite systems, comet families, the zodiacal cloud, the preplanetary nebula, etc. When the three-body problem is considered instead of individual orbits we are, now, looking for the topology of extended regions of its phase space. This Symposium was one step in the effort to close the ties between two scientific families: the observationally-oriented scientists and the theoretically-oriented scientists.

The concept of Stellar Populations has played a fundamental role in astronomy in the last few decades. It was introduced by Walter Baade after he was able to resolve the Andromeda Nebula and its companions into stars when he used red-sensitive plates and realised that there were two fundamentally different Herzsprung-Russell diagrams in our and these nearby galaxies (common stars in the solar neighborhood versus globular clusters). This result was published in two papers in 1944 in volume 100 of the Astrophysical Journal. Subsequent research gave the concept a much firmer basis and at the...

IAU symposium 165 'Compact Stars in Binaries' was held from 15 through 19 August 1994, as part of the 22nd General Assembly of the IAU in The Hague. The symposium, supported by IAU Commissions 35,37,44 and 48, and co-sponsored by Commission 42, was attended by about 400 to 500 participants. This symposium received support from: - The International Astronomical Union; - The Royal Netherlands Academy of Sciences; - The Netherlands Ministery of Education and Science; - The Leids Kerkhoven Bosscha Fonds; - The Stichting Fysica. The field of compact stars in binaries is one of the most active...

From the beginning of Space Astronomy, the Extreme Ultraviolet band of the spectrum (roughly defined as the decade in energy from 90-900 A) was deemed to be the unobservable ultraviolet'. Pioneering results from an EUV telescope on the Apollo-Soyuz Mission in 1975 forcibly demonstrated that this view was incorrect; but it required the all-sky surveys of the English Wide-Field Camera and the Extreme Ultraviolet Explorer to demonstrate the broad potential of this field. Over 700 EUV sources have now been detected.
Over 150 researchers from 16 countries gathered to share results in this...

In the past decade, indirect (Doppler) imaging techniques have opened up a whole new discipline in stellar astronomy, providing increasingly detailed photometric, magnetic, and chemical inhomogeneity images of stellar surfaces. Furthermore, new optical interferometers are already being used with sophisticated interferometer techniques to image stellar surface structures more directly, and in the future the ESO VLT Interferometer and other instruments will extend these capabilities enormously. These developments are highlighted in the first two sections of this book.
The large number of...

This volume reviews recent progress in the study of dynamics of star clusters. The meeting focused on the enormous progress of both the observation and the theoretical modeling of star clusters. New results from the refurbished Hubble Space Telescope (HST) include the mass function down to the hydrogen burning limits, white dwarf sequence, and central density profiles of post-collapse' clusters by star counts. On the theoretical side, this symposium saw the first direct evidence of gravothermal oscillation through N-body simulation, which was made possible by GRAPE-4, the dedicated...

IAU Symposium 172 Dynamics, Ephemerides and Astrometry of the Solar System was held in Paris in July, 1995. 250 scientists from 33 countries attended the symposium; 24 invited lectures and 165 contributed papers were presented (117 of which were posters). The papers covered topics on celestial mechanics (chaos and evolution of the solar system, asteroids, theories of the motion of the planets, the moon and the natural satellites), methods (symplectic mappings and elliptic functions), astrometry (CCD observations, VLBI and radar observations), ephemerides (representation and...

Molecules are found in a large variety of astronomical environments, ranging from comets in the solar system to galaxies at high redshift. This book brings together astronomers, physicists and chemists to discuss the use of molecules as probes of astrophysical parameters, explore their role in the evolution of astronomical objects, and study the basic chemical processes that occur in space. The enormous progress in observational techniques is illustrated by studies of the physics and chemistry on scales comparable to the protosolar nebulae around high- and low-mass forming stars and planetary...

The present decade is opening new frontiers in high-energy astrophysics. After the X-ray satellites in the 1980's, including Einstein, Tenma, EXOSAT and Ginga, several satellites are, or will soon be, simultaneously in orbit offering spectacular advances in X-ray imaging at low energies (ROSATj Yohkoh) as well as at high energies (GRANAT), in spectroscopy with increased bandwidth (ASCAj SAX), and in timing (XTE). While these satellites allow us to study atomic radiation from hot plasmas or energetic electrons, other satellites study nuclear radiation at gamma-ray energies (CGRO) associated...

Advanced technologies in astronomy at various wavelengths have provided us with high-resolution and high-quality data of the central regions of nearby galaxies and of the Milky Way Galaxy. These data, both for the Galaxy and extragalactic centers, are now quite suitable for detailed comparative study. This IAU symposium was aimed at understanding the general characteristics of dynamics, ISM physics and magnetic fields, activities including inflow and outflow, as well as starburst, in the galactic centers'. Special attention was also given to several cases for massive black holes in galaxies...