This volume contains papers presented at IAU Colloquium No. 90. at the Crimean Astrophysical Observatory in May of 1985. A few additional contributions are included from authors who for various reasons were unable to attend the meeting. Four years have passed since the last major international conference on chemically peculiar stars of the upper main sequence was held in Liege. Belgium in 1981. Previous conferences were held in 1975 (Vienna. Austria) and in 1965 (Greenbelt. Maryland. USA). As the proceedings of this Colloquium show. the recent availability of ultraviolet spectra of large numbers of normal and chemically peculiar A and B stars is having a major impact on the way we study these objects. and has led to many new. exciting and unanticipated results. Simultaneously. the more traditional study of optical spectra has been advanced through the increasing use of very high spectral resolution with high signal-to-noise detectors. The chemically peculiar (CP) stars on the upper main sequence belong in the standard framework within which we understand stellar evolution and the history of matter. Recent work has made it clear that the unusual chemistry and magnetic structure of these objects is of relevance across the broad domain of stellar astronomy. from the upper main sequence to horizontal branch stars and white dwarfs. Metal poor (J>. Boo) as well as metal rich (Ap. Am) stars are an integral part of the picture.

The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution. Such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. They are found to exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group, OB associations and as field stars. This book summarises the many advances in observational and theoretical work dedicated to blue straggler stars. Carefully edited extended contributions by well-known experts in the field cover all the relevant aspects of blue straggler stars research: Observations of blue straggler stars in their various environments; Binary stars and formation channels; Dynamics of globular clusters; Interpretation of observational data and comparison with models. The book also offers an introductory chapter on stellar evolution written by the editors of the book.

The papers in this study cover a range of scenarios, from disk and envelope around young stellar objects and protostars through to more aged stars and highly-evolved objects which exhibit considerable mass loss features. Significant advances and developments in observing facilities, instrumentation, computing power and techniques are described, together with a variety of theories, suggestions, observations and models. The formation, composition, effects and evolution of the material surrounding a stellar environment are also included.

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 massive stars take place in high lumi nosity beach resorts, and after Buenos Aires, Qualicum Beach, Cozumel and Porto Heli, Bali sounded like a reasonable place. Therefore we were only too pleased with the invitation of the Indonesian astronomical community to host the symposium in Sanur (Denpasar). The aim of the symposium was to bring together both observers and theoreticians active in the field of Wolf-Rayet stars and related objects, to present and discuss their recent results, in order to expose to what extent consensus exists as to the physical and chemical properties of Wolf-Rayet stars, their evolutionary status and their interrelations with other massive stars in galaxies."

H.T. MacGilLIVRAY Royal Observatory Blackford Hill Edinburgh EH9 3HJ Scotland U.K. lAU Symposium No. 161 on 'Astronomy from Wide-Field Imaging', held in Potsdam, Germany, during 23-27th August 1993, was the first conference organised by the recently-formed Working Group of lAU Commission 9 on 'Wide-Field Imaging'. This Working Group was instigated during the XXIst meeting of the General Assembly of the International Astronomical Union in Buenos Aires in 1991, and represented a merging of the former formal lAU Working Group on 'Astronomical Photography' and the informal 'Digitised Optical Sky Surveys' Working Group. Dr. Richard West was 'invited' to be Chairperson, and hence was given the daunting task of organising the Group from scratch. The very fact that the first conference after only two years was a major lAU Symposium says much about the determination and enthusiasm of Richard West to fulfilling the aims of the new Working Group. The siting of the conference in Potsdam in formerly East Germany provided an excellent opportunity to advantage from the political changes in Eastern Europe. Good access to the meeting was possible by scientists from Eastern European countries, allowing exchange of information on the very important Wide-Field facilities in both East and West, information on the rich archives of photographic plates that exist in both East and West, and allowing discussions between scientists facing very similar problems in both East and West.

"If you buy just one guide...you won't do better than this" - BBC Sky at Night Magazine "I will continue to enjoy 'Philip's Stargazing' as the months go by" - Helen Sharman, Astronaut "Very useful indeed" - Chris Lintott, Sky at Night presenter Discover the latest in stargazing with the new and definitive guide to the night sky. Whether you're a seasoned astronomer or just starting out, Philip's Stargazing 2022 is the only book you'll need. Compiled by experts and specially designed for use in Britain and Ireland, Stargazing 2022 acts as a handily illustrated and comprehensive companion. - 12 Brand-New Maps for year-round astronomical discovery - Month-to-Month information. Daily Moon Phase Calendar, highlighting special lunar events throughout the year - Planet Watch for ideal viewing days in 2022 - Avoid light pollution with our detailed Dark Sky Map - Expert advice and insight throughout from internationally renowned Professor Nigel Henbest - A 'Behind the Scenes' look at astrophotography from expert Robin Scagell - Complete calendar of major astronomical events, including the Top 20 Sky Sights of 2022 - Jargon Buster, explaining common or confusing terms - The planets' movements explained from solar and lunar eclipses to meteor showers and comets

The motivation for the workshop on which this book is based was the discovery in recent years of a large number of binary and millisecond radio pulsars, in the galactic disk as well as in globular star clusters, the oldest stellar systems in our galaxy. These discoveries have revolutionized our thinking on many aspects concerning the interior structure and evolution of neutron stars, and have revived the interest in the study of neutron star physics in general. In this book some three dozen of the world's experts in the field of radio pulsars, X-ray binaries, stellar evolution, neutron star interiors and stellar dynamics review the latest observational discoveries as well as the current theoretical thinking on the formation and physics of binary X-ray sources and of the binary and milli-second pulsars. These include discoveries such as that of the elevent millisecond pulsars in the globular cluster 47 Tucanae, the relativistic effects in the new double neturon star system PSR 1534+12 and spectacular results from Germany's ROSAT X-Ray Observatory.

Foreword; J. Davies, D. Burstein. Introductory Remarks; M. Disney. Interstellar grain evolution and temperatures in spiral galaxies; J. Mayo Greenberg, A. Li. Radiative transfer models; G. Bruzual A. Radiative transfer in dusty galaxies; A.N. Witt. Opacity Diagnostics in spiral galaxies; N.D. Kylafis. Modeling dusty galaxies; G. Magris C., G. Bruzual A. Inclination-dependence of spiral galaxy physical properties: history and tests; D. Burstein, et al. Why a distance selection effect invalidates the Burstein, Haynes and Faber opacity test; J.I. Davies, et al. Statistical tests for opacity; E.A. Valentijn. Statistical measures of internal absorption in spiral galaxies; B. Cunow. The distribution of galactic inclinations; H. Jones, et al. Optical thickness of Sb-Scd galaxies from the Tully--Fisher relation; L. Gouguenhei, et al. Extinction in Sc galaxies at I band and in the 21cm line; R. Giovanelli. Extinction in the galaxy and in galactic discs; G. de Vaucouleurs. Properties of dust in backlit galaxies; W. Keel, R.E. White. The optical depth through NGC 3314A; P. James, P. Puxley. Dust extinction in highly inclined spirals; J. Knapen, et al. An optical search for dusty disks; M. Naslund, S. Joersater. Photometric asymmetry and dust opacity of spiral galaxies; Y.I. Byun. The scale-length test for dust in face-on spirals; J.E. Beckman, et al. Color gradients in spiral galaxies; S. Courteau, J. Holtzman. Constraints on the opacity of spiral disks from near-infrared observations; H.W. Rix. Arcsecond resolution of cold dust in spiral galaxies using optical and NIR imaging -- dust masses increase by nine hundred percent; D.L. Block, et al. Unveiling stars and dust in spiral galaxies;R.F. Pelletier, et al. Azimuthal distribution of dust in NGC 2997; P. Grosbol, et al. Internal extinction in spiral galaxies at optical and near infrared wavelengths; A. Boselli, G. Gavazzi. The opacity of spiral galaxy disks; N. Devereux. The far infrared/stellar energy balance; R. Evans. Opacity from luminosity functions; M. Trewhella, et al. Estimating disk opacities using infrared images; W. van Driel. DIRBE observations of galactic extinction; R.G. Arendt, et al. Kinematics of edge-on galaxies and the opacity of spiral disks; A. Bosma. Spectroscopic studies of the disk and halo of M82; C.D. McKeith, et al. Disk origin and evolution; J. Silk. The luminosity and opacity of galaxies; B. Wang. Dust obscuration in starburst galaxies; D. Calzetti. Polarimetry of dusty edge-on galaxies; R.D. Wolstencroft, S.M. Scarrott. HII regions and extinction in the spiral galaxy M83; S. Ryder, et al. A search for dust in galactic halos; D. Zaritsky. Concluding thoughts and reflections: dust in galaxies; H.A. Thronson Jr.

Planetary nebulae are a keystone for the understanding of the evolution of stars, for deep insights into the physical processes prevailing in highly excited dilute nebulae, and for the chemical evolution in galaxies. These objects, displaying an intriguing morphology, have a "short" lifetime of a few tens of thousands of years, and have become one of the best studied classes of celestial sources. However, despite large and successful efforts from both the observational and theoretical side, planetary nebulae still keep some of their secrets (like the widely unknown distances) and will undoubtedly also be objects of thorough investigations in the years to come.

Fundamental unsolved problems of stellar astrophysics include the effects of angular momentum on stellar structure and evolution, the nature and efficiency of the processes by which angular momentum is redistributed within and lost from stars, and the role that stellar rotation plays in enhancing or driving stellar mass loss. There appears to be a qualitative change in the nature and efficiency of these mechanisms near spectral type FO: hotter (more massive) stars typically retain more angular momentum at least until they reach the main sequence, while cooler stars typically spin down quickly. For the hotter stars, recent work suggests a strong link between the type of pulsation behavior, the mass loss rates, and the rotation velocity. If the same mechanisms are able to drive mass loss from the main sequence A stars, as has recently been proposed, then the current interpretations of a number of observations will be drastically affected: e. g. the ages of clusters may be incorrect by up to a factor of two, and the surface abundances of isotopes of He, Li and Be may no longer give constraints on cosmological nucleosynthesis. There are also effects on the evolution of the abundances of elements in the interstellar medium and on the general evolution of populations of stars. Thus the questions of the mechanisms of angular momentum and mass loss of stars more massive than the sun is important not only for stellar studies but for the foundations of much of modern astrophysics.

Stellar Physics is a rather unique book among the growing literature on star formation and evolution. Not only does the author, a leading expert in the field, give a very thorough description of the current knowledge about stellar physics but he handles with equal care the many problems that this field of research still faces. A bibliography with well over 650 entries makes this book an unparalleled source of references.Fundamental Concepts and Stellar Equilibrium is the first of two volumes, and can be read, as can the second volume, as an independent work. It provides an extensive introduction into all physical processes that play a role in star formation and evolution. The basic equations describing stellar equilibrium are discussed, where attention is paid to both the theoretical and the numerical aspects.

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.

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.

The international Colloquium "Open Issues in Local Star Formation and Early Stellar Evolution" was held in Ouro Preto (Brazil) from April 05to10, 2003. TheColloquiumtookplaceinthe"ParqueMetalurgico", ' an old iron industry that has been transformed into a nice modern c- ference center. Ouro Preto is a 18th century colonial city that has been declared a Cultural Heritage of Mankind in 1980. It is situated in the hills of the State of Minas Gerais at about 100 km from Belo Horizonte. Themeeting was attended by 115 participants from 15 countries. The participants were in general very happy with the high level of the p- sentations and with the friendly ambiance of the discussions. The talks and poster sessions were focused on the physics of young stellar objects, which are being observed with increasing angular resolution provided by the new generation of telescopes, and on the processes that triggered large scale star-formation in the solar neighborhood or in the Galaxy.

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 process of their formation. or shortly afterwards. This fourth workshop organized by the "Advanced School ot Astronomy was indeed centered on the "Spectral Evolution of Galaxies." on reviewing and discussing the relevant astrophysical processes and on assessing our current ability to model and understand the evolution of stellar populations. Following an opening session dealing with some outstanding questions of galaxy evolution. Session I addressed the specific problems of galaxy and star formation processes. topics of uncertainty and controversy to which IRAS observations may give novel perspectives. The properties of stellar populations in the local group of galaxies formed the basis of Session II. Session III dealt with the fundaments of the theory of spectral and photometrical evolution of stellar populations. and with recent developments in the theory of stellar structure. a necessary step to model and understand galactic evolution.

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 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.

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

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.

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.