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 special-purpose computer for N-body simulation. Numerical techniques to combine stellar evolution and dynamical evolution of the cluster were presented. The book will be of primary interest to astrophysicists.

This book represents the Proceedings of the NATO Advanced Study Insti tute on Formation and Evolution of Low Mass Stars held from 21 September to 2 October 1987 at Viana do Castelo, Portugal. Holding the meeting in Portugal recognized both the historical aspects and the bright future of astronomy in Portugal. In the early sixteenth century, the Portugese played an important role in the critical diffusion of classical and medieval knowledge which formed so large a part of scientific activity at that time. Navigation and course setting, brought to a high level by Portugese explorers, relied on mathematics and astronomy to produce precise tables of solar positions. In contemporary Portu gal, astronomy is the focus of renewed interest and support at the universities. It is thus particularly appropriate that the NATO Advanced Study Institute was held on the coast of the Atlantic Ocean in the friendly surroundings of the Costa Verde.

The IAU Colloquium No. 59, "The effects of mass loss on Stellar Evolution" was held on September 15-19, 1980 at the International Centre for Theoretical Physics, Miramare, Trieste (Italy), under the auspices of the IAU Executive Co~ mittee and the Italian National Council of Research. The planning of this conference began two years ago du ring the IAU Symposium No. 83 "Mass loss and evolution of 0 type stars" (Qualicum Beach, Victoria, Canada) when we felt that mass loss and its effects on the evolution of stars was too broad a subject for being confined to 0 type stars only. Therefore we thought that a conference dealing with the general problem of mass loss across the whole HR diagram would have been of interest to all people working in the field. The main idea was that bringing together Astronomers and Astrophysicists of the widest range of interests and e~ pertize - all in some way related to the problem of mass loss from stars - would have spurred thorough discussions on the many aspects and implications of this topic. We hope this goal has been achieved. Furthermore, the most recent observational and theoreti cal developments on the problem of mass loss from early ty pe stars avoided this meeting to be a simple updating of the Qualicum Beach Symposium as far as this issue is concerned.

The idea for an international symposium on the interstellar medium was first discussed at the University of Wyoming during the summer of 1984. It was obvious that the outstanding natural beauty of the Teton mountain range in northwestern Wyoming must be matched by a meeting with the broadest appeal to the astronomical community. If the meeting was to produce a book, it must likewise be an important contribution to the astronomical literature. It was for these reasons that early in the discussions, it was decided that the University should host a "school". with the invited speakers presenting tutorials on a broad range of topics involving the interstellar medium. The symposium proceedings would then be a compilation of the written versions of these presentations. It has been nearly a decade since Lyman Spitzer published his classic text on the interstellar medium and we felt the need for a school and book that would focus on the recent developments in our understanding of the inter stellar medium. Thus, we view this two-volume set as an adjunct text to Spitzer's book.

The idea to hold a conference on the Evolution of Close-Binary X-ray sources grew in the summer of 1984. At that time we were hoping that some new results would be harvested in the months to come which would stimulate further work. We were particularly looking towards the Euro pean X-ray Observatory, EXOSAT, for new contributions. How lucky we were; quite unexpected developments took place. Just prior to the conference, quasi-periodic oscillations (now known as QPO) were discovered in three bright low-mass X-ray binaries: GX 5-1, Sco X-1, and Cyg X-2. They played an important role at the meeting. The possibility that QPOs imply a neutron star magnetic dipole field, and a neutron star rotation period in the millisecond range, received a lot of attention. This is not surprising, as it lends support to the idea, suggested earlier, that the 6-msec binary radio pulsar PSR 1953+29 evolved from a stage in which it was a bright low-mass X-ray binary. There was special interest in the possibility of white dwarf collapse into a neutron star. This is a. particularly attractive way to form the bright low-mass X-ray binaries, often referred to as galactic bulge sources. It would allow for the possibility of a very young neutron star in a very old binary system. The relatively high magnetic fields that one could infer from QPO could then be explained."

Proceedings of IAU Symposium No. 75 held in Geneva, Switzerland, September 6-10, 1976. Dedicated to Solomon Pikel'ner

This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.

The Pacific Rim Conference originally started with one research concentration only - binary star research. The first Conference was held in Beijing, China, 1985, the second one in Seoul and Taejon, South Korea, 1990 and the third one in Chiang Mai, Thailand, 1995. In recent years, the conference series evolved into a much broader area of stellar astrophysics. The first such conference was held in Hong Kong in 1997. Kwong-Sang Cheng, a. k. a. one of the three Musketeers, documented the "accidental" development in writing in the Proceedings of the 1997 Pacific Rim Conference on Stellar Astrophysics (Volume 138 of the ASP Conference Series)! The meeting at Hong Kong University of Science and Technology covered three major topics: binary stars, compact stars and solar type stars. The conference was extremely successful. There was a general feeling among the participants that the conference on stellar astrophysics provided a good means to share ideas between such closely related disciplines. Unfortunately after the very successful meeting at HKST, Kwing L. Chan (another Musketeer) thought that he had already served and would not like to chair for another LOC for at least five years! After a few drinks at one of the watering holes in Wan Chai district of Hong Kong, Kwong-Sang Cheng was in very hiRh spirit and volunteered to taking on the responsibility of hosting the 51 Pacific Rim Conference at Hong Kong University in 1999.

Planetary nebulae are the classic subject of astrophysics. The physical pro cesses occurring in this highly ionized gaseous medium, the formation of emis sion lines in clearly specified conditions, the continuous emission extending from the far ultraviolet up to infrared and radio frequencies, the generation of exotic forms of radiation predicted by atomic physics, along with methods for deciphering the observed spectra and detecting physical and kinematic parameters of the radiating medium, etc. - all these problems form the solid foundations of the physical theory of gaseous nebulae. They are an essential part of the arsenal of powerful tools and concepts without which one cannot imagine understanding and interpreting the enormous diversity of processes taking place in the Universe - in gaseous envelopes surrounding the stars of various classes, from cool dwarfs and flare stars up to hot supergiants, as well as in stellar chromospheres and coronae, in atmospheres of unstable and anomalous stars, in circumstellar clouds and gaseous shells born in nova and supernova explosions, in diffuse nebulae and the interstellar medium, in interacting binary systems, in galaxies with emission lines, in quasars, etc. The last thirty years have seen a turning-point in our knowledge concern ing the very nature of planetary nebulae (PNs). The radio emission of PNs was discovered after it was predicted theoretically. On the other hand, the powerful infrared emission discovered both in the continuum and in emission lines was never expected."

Solid particles are followed from their creation through their evolution in the Galaxy to their participation in the formation of solar systems like our own, these being now clearly deduced from observations by the Hubble Space Telescope as well as by IR and visual observations of protostellar disks, like that of the famous Beta Pictoris object. The most recent observational, laboratory and theoretical methods are examined in detail. In our own solar system, studies of meteorites, comets and comet dust reveal many features that follow directly from the interstellar dust from which they formed. The properties of interstellar dust provide possible keys to its origin in comets and asteroids and its ultimate origin in the early solar system. But this is a continuing story: what happens to the solid particles in space after they emerge from stellar sources has important scientific consequences since it ultimately bears on our own origins - the origins of solar systems and, especially, of our own earth and life in the universe.

More than half of all stars in the universe formed and evolved as binary systems and their study is essential for understanding stellar and galactic evolution. The six lectures in this book give both a readable introduction and an up-to-date review of nearly all aspects of research into binary stars, including the range from common binaries to more exotic systems composed of white dwarfs, neutron stars and black holes.

Written by an international team of experts, this set of tutorial reviews provides a coherent and accessible summary of the current state of supernova research in all of its facets. The newly detected gamma-ray bursts are discussed in this context. While primarily addressing astrophysicists and astronomers, this book will also be of interest to cosmologists and nuclear physicists working on supernova-related issues.

This volume presents results from the ESO workshop Multiple Stars across the H-R Diagram, held in Garching in July 2005. It covers observations of multiple stars from ground and space, dynamical and stellar evolution in multiple systems, formation and early evolution of multiple stars, and special components of multiple stars. The book reviews the current state of observational and theoretical knowledge and discusses future studies for further progress in the field.

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

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 and the Galaxy, and to understanding the physics of nuclei associated with black holes.

Classical stellar evolution theories have undergone some drastic changes in recent decades. New insights into the development of stellar interiors were obtained from studying stars in various stages of their lives, as well as with the help of fast computers, which gave a boost to the branch of numerical modelling of stellular structure and evolution. This book is divided into two parts. The first part deals with the general aspects of stellular structure and evolution including a chapter on numerical modelling. The second part deals with specific evolutionary aspects of single and binary stars with a variety of masses. The last chapter gives several models of stars with specific masses. The book is intended as an introduction for students, as well as a reference for researchers.

The symposium on "Neutral Clouds near HII Regions" was prompted by an obvious need to bring together workers specifically interested in the dynamical and photochemical effects in regions showing clear evidence of on-going star formation. This is currently an are a of considerable research activity with much new observational material over the wavelength range from X-ray to radio. Furthermore, the field isbeginning to mature. No longer is molecular spectroscopy concerned only with the search for new lines and with preliminary surveys. No longer are evolving HII regions modelled with the naive assumption of constant density. Similarly, ideas of successive star formation, "champagne" and "blister" models of HII regions, and refinements to abundance calculations are examples which show that theoretical initiative is keeping pace. We were both surprised and gratified by the number of contributed papers and the extent to which they addressed the subject matter. In the proceedings we have grouped these papers near the most appropriate of the four invited review papers. The subjects of these reviews are in the general areas of "Evolution of HII Regions," "Dynamical Interactions," "Chemistry in Active Regions" and "Infrared and Maser Sources." The symposium comprised 42 orally presented papers and 23 poster papers. AII but two are reproduced in this volume.

In recent years, it has become clear that the red-giant phase is one of the most dramatic periods in a star's life, when all of its parts become involved in ways that have both direct and indirect observational consequences. This is most particularly true of low- and intermediate mass stars during the second ascent of the giant branch. Such stars bring to their surfaces products of nucleosynthesis currently taking place in their deep interiors, they pulsate as Mira variables, develop extended outward-flowing atmospheres that may exhibit maser properties, and shed great quantities of matter, sometimes highly processed, into the inter stellar medium. The manner in which processed matter is brought to the surface is far from being completely explained, and the precise mechanism or mechanisms whereby matter is ejected from the stellar surface (whether by deposition of Alfven waves, radiation pressure on grains, or as a consequence of so me large scale envelope instability) has yet to be elucidated to every one's satisfaction. The purpose of the second workshop in Astrophysics, organized by the "Advanced School of Astronomy," was to bring together experts on all the physical processes occurring in red giants in an effort to emphasize the interrelatedness of these individual processes, and to encourage a dia logue among experts that might serve to initiate a synthesis, or at least sharpen our understanding of the most important problems to address in the future."

This book records our current understanding of the observational and theoretical properties of objects known as ultracool dwarfs. It covers the state of the art in this new field. It is split into theoretical, observational and spectral classification sections. Each subject area begins with an introduction by an eminent scientist. It covers a wide range of issues, such as the transition from L to T dwarfs, dust and alkali metal modelling, companions, activity, the deuterium test, and brown dwarf variability, and contains considerable discussion about spectral classification schemes. The articles arose from an IAU meeting and they address researchers as well as graduate students.

Our conference - opening today - has two aims in view: first, to commemorate some milestones in the development of the studies of close binary systems whose anniversaries fall in these years, as well as to take stock of our present knowledge accumulated through out preceding decades, in order to consider where do we go from here. This summer, 310 years will have elapsed since the first ec lipsing binary - Algol - was discovered in Bologna by Geminiano Montanari (1633-1687) to be a variable star; and 198 years have gone by since John Goodricke of York (1764-1786) established the fact that Algol's light changes were periodic. Moreover, it is al most exactly (to a month) now 100 years since Edward Charles Pickering (1846-1919) of Harvard Observatory in the United States took the first steps towards the development of systematic methods of analysis of the light changes of Algol and related systems - a topic which will constitute the major part of the programme of our present conference. The three dates recalled above illustrate that the discoverers of such celestial objects and observers of their light changes have been systematically ahead of the theoreticians endea vouring to understand the significance of the observed data by de cades and centuries in the past - a fact which, incidentally, con tinues to hold good (albeit with a diminishing lead-time) up to the present."

The book gives an extended review of theoretical and observational aspects of neutron star physics. With masses comparable to that of the Sun and radii of about ten kilometres, neutron stars are the densest stars in the Universe. This book describes all layers of neutron stars, from the surface to the core, with the emphasis on their structure and equation of state. Theories of dense matter are reviewed, and used to construct neutron star models. Hypothetical strange quark stars and possible exotic phases in neutron star cores are also discussed. Also covered are the effects of strong magnetic fields in neutron star envelopes and a comparison on neutron star models with observations.

This book is based partly on a. lecture course given at the University of Tri este, but mostly on my own research experience in the field of galactic chemical evolution. The subject of galactic chemical evolution was started and developed by Beat rice Tinsley in the seventies and now is a flourishing subject. This book is dedi cated to the chemical evolution of our Galaxy and aims at giving an up-to-date review of what we have learned since Tinsley's pioneering efforts. At the time of writing, in fact, books of this kind were not available with the exception of the excellent book by Bernard Pagel on "Nucleosynthesis and Chemical Evolution of Galaxies" (Cambridge University Press, 1997), and the subject of galactic chem ical evolution has appeared only as short chapters in books devoted to other subjects. Therefore, I felt that a book of this kind could be useful. The book summarizes the observational facts which allow us to reconstruct the chemical history of our Galaxy, in particular the abundances in stars and in terstellar medium; in the last decade, a great deal of observational work, mostly abundance determinations in stars in the solar vicinity, has shed light on the pro duction and distribution of chemical elements. Even more recently more abun dance data have accumulated for external galaxies at both low and high redshift, thus providing precious information on the chemical evolution of different types of galaxies and on the early stages of galaxy evolution."

All theoretical and observational topics relevant to the understanding of the thermonuclear (Type Ia) supernova phenomenon are thoroughly and consistently reviewed by a panel including the foremost experts in the field. The book covers all aspects, ranging from the observations of SNe Ia at all stages and all wavelengths to the 2D and 3D modelling of thermonuclear flames in very dense plasmas. Scenarios for close binary evolution leading to SNe Ia are discussed. Particular emphasis is placed on the homogeneity vs. diversity of SNe Ia and on their use as standard candles to measure cosmological parameters. The book reflects the recent and very significant progress made in both the modelling of the explosions and in the observational field.

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

IAU Symposium No. 121 was hosted by the Byurakan Astrophysical Observatory in Soviet Armenia, almost 30 years after Ambartsumian's pioneering ideas about galaxy activity were first published and almost exactly 20 years after the first Byurakan IAU symposium on nuclear activity (No. 29, "Non-stable Phenomena in Galaxies, May 1966). Although the proceedings of the first Byurakan symposium were not published in English, that conference provided a definitive impulse to the field, as Ambartsumian's ideas had done 10 years earlier. The Byurakan Astrophysical Observatory was thus a particularly appropriate setting for IAU 121. The symposium was also very timely since many new exciting results were presented which will surely revolutionize many of our present ideas about nuclear activity in galaxies and QSO's. The first results of the by now famous Markarian survey were presented by B.E. Markarian in the first Byurakan conference. Unfortunately, his untimely death prevented him from attending the second conference, but the influence of his fundamental work was certainly felt.