The accretion process is thought to play a key role in the Universe. This book explains, in a form intelligible to graduate students, its relation to the formation of new stars, to the energy release in compact objects and to the formation of black holes. The monograph describes how accretion processes are related to the presence of jets in stellar objects and active galactic nuclei and to jet formation. The authors treat theoretical work as well as current observational facts. This volume of the highly esteemed Les Houches series is meant as an advanced text that can serve to attract students to exciting new research work in astrophysics.

We stand at the threshold of an exciting era of Asteroseismology. In a few months' time, the Canadian small-satellite asteroseismology mission MOST will be laun ched. Danish and French missions MONS and COROT should follow, with the ESA mission Eddington following in 2007/8. Helioseismology has proved spec tacularly successful in imaging the internal structure and dynamics of the Sun and probing the physics of the solar interior. Ground-based observations have detected solar-like oscillations on alpha Centauri A and other Sun-like stars, and diagnostics similar to those used in helioseismology are now being used to test and constrain the physics and evolutionary state of these stars. Multi-mode oscillations are being observed in an abundance of other stars, including slowly pulsating B stars (SPB stars), delta Scuti stars, Ap stars and the pulsating white dwarfs. New classes of pulsators continue to be discovered across the Hertzsprung-Russell diagram. For good reason it was decided to entitle our conference 'Asteroseismology Across the HR Diagram' . Yet the challenges still to be faced to make asteroseismology across the HR diagram a reality are formidable. Observation, data analysis and theory all pose hard problems to be overcome. In conceiving this meeting, the aim of the organisers was to facilitate a cross-fertilization of ideas and approaches between researchers working on different pulsators and with different areas of expertise. We venture to suggest that in this the conference was a great success."

Quasars, and the menagerie of other galaxies with "unusual nuclei," now collectively known as Active Galactic Nuclei or AGN, have, in one form or another, sparked the interest of astronomers for over 60 years. The only known mechanism that can explain the staggering amounts of energy emitted by the innermost regions of these systems is gravitational energy release by matter falling towards a supermassive black hole --- a black hole whose mass is millions to billions of times the mass of our Sun. AGN emit radiation at all wavelengths. X-rays originating at a distance of a few times the event horizon of the black hole are the emissions closest to the black hole that we can detect; thus, X-rays directly reveal the presence of active supermassive black holes. Oftentimes, however, the supermassive black holes that lie at the centers of AGN are cocooned in gas and dust that absorb the emitted low energy X-rays and the optical and ultraviolet light, hiding the black hole from view at these wavelengths. Until recently, this low-energy absorption presented a major obstacle in observational efforts to map the accretion history of the universe. In 1999 and 2000, the launches of the Chandra and XMM-Newton X-ray Observatories finally broke the impasse. The impact of these observatories on X-ray astronomy is similar to the impact that the Hubble Space Telescope had on optical astronomy. The astounding new data from these observatories have enabled astronomers to make enormous advances in their understanding of when accretion occurs."

This volume is written by leading scientists in the field, who review the current state of our knowledge of tidal streams in the Milky Way, the Andromeda galaxy, and in other nearby galaxies. The cosmological origins of dwarf galaxies and the physical processes by which they are tidally disrupted into streams and incorporated into galaxy halos are discussed. The techniques that have been used to identify tidal streams are presented and will be useful to researchers who would like to find substructures in the next generation of optical sky surveys, including Pan-STARRS and LSST. The methods that are currently under development to constrain both large scale distribution of dark matter in the Milky Way and the (small scale) lumpiness of the dark matter distribution are also explained. The authors also provide motivation for future spectroscopic surveys of Milky Way halo stars, which will aid both in the identification of tidal streams and the constraint of dark matter properties. This volume is aimed at graduate students who are beginning this field of research, but is also a resource for researchers who study tidal streams and related fields. In addition to presenting the physical processes by which tidal streams are created, it also reviews the current state of the observations and the progress towards utilizing these observations to constrain the distribution of dark matter in the Milky Way. The book will introduce anyone with a background in astrophysics to the field of tidal streams.

This Atlas provides a complete set of images of Local Group Galaxies (excluding the three for which identification atlases are already in print) and shows the most important objects, including many thousands of individual stars and interstellar objects.

It is unique in its coverage and format and provides a source of these fundamental data that will be used for many years. Researchers, students and even amateur astronomers will be able to use the Atlas to identify and study the various components of the nearly 30 important galaxies covered by the Atlas.

The objects identified on the more than 200 charts include variable stars, globular star clusters, open star clusters, stellar associations, emission regions, supernova remnants, planetary nebulae and dust clouds. Each galaxy is accompanied by an extensive bibliography.

Papers of the Paris meeting in June 1990 on Local Group Galaxies, molecules in early-type galaxies, observations of spiral structure in molecular clouds, a comparison with other gaseous components and IR emission, interacting galaxies and starbursts, gas and star dynamics, galaxy evolution, IRAS ult

White dwarfs, neutron stars, and (solar mass) black holes are the collapsed cores of stars which, near the ends of their luminous lives, have shed most of their mass in supernova explosions or other, less spectacular, instabilities. Here gravity crushes matter to realms that lie far beyond present empirical knowledge. This book explores the diverse forms that such compact stars can possibly take, as constrained by the laws of nature: the general principles of relativity and quantum mechanics, the properties of nuclear matter deduced from nuclei, and the asymptotic freedom of quarks at high density. The book is self contained. It reviews general relativity, essential aspects of nuclear and particle physics, and general features of white dwarfs, neutron stars and black holes; it includes background on such matters as stellar formation and evolution, the discovery of pulsars and associated phenomena, and the strange-matter hypothesis. The book develops a theory for the constitution of neutron stars and the more exotic Hyperon Stars, Hybrid Stars (containing a quark matter core surrounded by an intricate lattice of quark and hadronic matter) and Strange Stars and Dwarfs (composed of the three light quark flavors sheathed in a solid skin of heavy ions). This second edition has been revised throughout to clarify discussions and bring data up to date; it includes new figures, several new sections, and new chapters on Bose condensates in neutron stars and on phase transitions.

This volume contains the Proceedings of the Fourth Scientific Meeting of the Spanish Astronomical Society (Sociedad Espanola de Astronomfa, SEA). The meeting was held at the Universidade de Santiago de Compostela in Galicia from September 11 to 14, 2000. The event brought together 156 participants who pre- sented their latest results in many different subjects. In comparison with the previous scientific meetings of the Society, the numbers of oral talks and poster contributions (95 and 51, respectively) are rapidly increasing, confirming that the SEA conferences are becoming a point of reference to assess the interests and achievements of astrophysical research in Spain. During the meeting, the SEA made public the granting of the Prize to the Best Spanish Ph. D. Thesis in As- tronomy and Astrophysics for the period 1998-1999 to Dr. H. Socas. This is the first time that the SEA is awarding this prize, which aim is to encourage young spanish astrophysicists to pursue a high level scientific career. The Society is indebted to the Universidade de Santiago de Compostela, and, in particular, to the Observatorio Astronomico Ramon Marfa Aller, for its hospi- tality. The Local Organizing Committee took care of all the logistics details to ensure a nice stay for all the participants. The effort of the Scientific Organizing Committee was decisive in determining the organizational and scientific success of the meeting.

There are as many different kinds of stars as there are stars themselves. Each an individual, every one unique. In this arresting and lavishly illustrated volume, noted astronomy writer and teacher Jim Kaler choose 100 stars to illustrate the mind-boggling variety of the stars' shapes and sizes, their immense ages, and the vast range of configurations in which they exist.||From AG Draconis to Z Andromedae, this alphabetically arranged volume first lists each star's resident constellation, its class, its apparent brightness as viewed from Earth, its distance from our Sun, and its visual luminosity. Then the real story begins. In choosing his "top 100," Kaler has aimed not just at providing a representative sample of the Universe's extraordinarily diverse population, but at capturing their complexity, their dynamism, and the amazing view they provide into the extraordinary physical forces at play in the Universe.||James B. Kaler is Professor of Astronomy at the University of Illinois at Urbana-Champaign. He has held both Fulbright and Guggenheim Fellowships, and has been awarded medals for his work from the University of Liege (Belgium) and the University of Mexico. He is the author of six books and dozens of articles on astronomy, including The Little Book of Stars (Copernicus Books, 2000) and lectures frequently. He also directs and maintains several educational websites, including the highly regarded and award-winning "Stars of the Week" site at the University of Illinois: http://www.astro.uiuc.edu/~kaler/sow/sow.html.||Reviews:||¿Most people know about Sirius, Canopus and Antares, but not everyone will be familiar with EG 129, HZ 21 and Polaris Australis, the dim star close to the south pole of the sky. Enter The Hundred Greatest Stars by James Kaler...Following a very clear general introduction to stellar astronomy, Kaler embarks on an informative tour through his hundred favourite stars, each given a page of text with an appropriate illustration on the facing page¿The really clever aspect of the book is that as well as describing the hundred stars, often bringing out aspects which are unfamiliar, Kaler succeeds in giving an excellent broad survey of recent developments in stellar astronomy. As is to be expected, the text is immensely authoritative¿The illustrations are beautiful...¿|¿New Scientist

Black hole gravitohydromagnetics (GHM) is developed from the rudiments to the frontiers of research in this book. GHM describes plasma interactions that combine the effects of gravity and a strong magnetic field, in the vicinity (ergosphere) of a rapidly rotating black hole. This topic was created in response to the astrophysical quest to understand the central engines of radio loud extragalactic radio sources. The theory describes a "torsional tug of war" between rotating ergospheric plasma and the distant asymptotic plasma that extracts the rotational inertia of the black hole. The recoil from the struggle between electromagnetic and gravitational forces near the event horizon is manifested as a powerful pair of magnetized particle beams (jets) that are ejected at nearly the speed of light.

This second edition of the book is updated throughout and contains a completely new chapter discussing state of the art and results of numerical simulations of ergospheric disk jets occurring in magnetohydrodynamic accretion flows.

The objective of this workshop was to put together observational and theoretical works on outflows from different kinds of astrophysical objects, occurring on different scales and at various evolutionary phases, and to discuss the impact of observations from future space missions. For the stars, we thought to follow throughout the evolution the relevance (rates and dynamical rrodes) of the mass loss phenomenon, e. g. to explain how and when massive stars loose most of their ini tial mass to end up with typical WD masses. The observations of the solar wind were included for being a unique case where the origin and propagation of the outflow can be resolved. We thought that the comparison with similar phenomena occurring in galactic outflows would be fruitful, as demonstrated by recent works on galactic winds and jets. The interest of having this workshop in Torino came because there are groups in this area, at the Astronomical Observatory and at the Institute of Physics of the University, involved in the theoretical and observational studies of outflows from astrophysical objects. The members of the Scientific Organizing Conmi ttee were: V. Castellani, C. Cesarski, P. Conti, A. Ferrari, A. Gabriel, M. Grewing, Y. Kondo, H. Lamers, V. Manno, M. Rees and R. Schilizzi. The Local Organizing Conmi ttee was: L. Bianchi, G. Massone and E. Antonucci. During the workshop the following topics were treated: the solar wind, the mass loss from cool stars and from hot stars (m. s.

It has been more than five decades ago that Henk van de Hulst predicted the observability of the 21-cm line of neutral hydrogen (HI ). Since then use of the 21-cm line has greatly improved our knowledge in many fields and has been used for galactic structure studies, studies of the interstellar medium (ISM) in the Milky Way and other galaxies, studies of the mass distribution of the Milky Way and other galaxies, studies of spiral struc ture, studies of high velocity gas in the Milky Way and other galaxies, for measuring distances using the Tully-Fisher relation etc. Regarding studies of the ISM, there have been a number of instrumen tal developments over the past decade: large CCD's became available on optical telescopes, radio synthesis offered sensitive imaging capabilities, not only in the classical 21-cm HI line but also in the mm-transitions of CO and other molecules, and X-ray imaging capabilities became available to measure the hot component of the ISM. These developments meant that Milky Way was no longer the exclusive playground for ISM studies and that by reaching out to other galaxies astronomy had gained the advantage of having an "outside" view, though at the expense of giving up some linear resolution. Studies of the ISM in other galaxies are intimately connected to studies of the ISM in the Milky Way."

Light scattering and absorption by small homogeneous particles can be worked-out exactly for spheres and infinite cylinders. Homogeneous particles of irregular shapes, when averaged with respect to rotation, have effects that can in general be well-approximated by reference to results for these two idealised cases. Likewise, small inhomogeneous particles have effects similar to homogeneous particles of the same average refractive index. Thus most problems can be solved to a satisfactory approximation by reference to the exact solutions for spheres and cylinders, which are fully stated here in the early part of the book. The sum of scattering and absorption, the extinction, is too large to be explained by inorganic materials, provided element abundances in the interstellar medium are not appreciably greater than solar, H 0 and NH3 being essentially excluded in the 2 general medium, otherwise very strong absorptions near 3p, m would be observed which they are not. A well-marked extinction maximum in the ultraviolet near 2200A has also not been explained satisfactorily by inorganic materials. Accurately formed graphite spheres with radii close to O.02p, m could conceivably provide an explanation of this ultraviolet feature but no convincing laboratory preparation of such spheres has ever been achieve

1. The Workshop and this Tome In the excellent bucolic setting of SchloB Ringberg in Upper Bavaria, over 50 scientists assembled during the week of 23-28 September 1996 to discuss recent results, both theoretical and observational in nature, on the large scale structure of the Universe. Such a topic is perhaps nowadays far too encompassing, and is essentially all of what we used to call "observational cosmology. " The original philosophy of the organization of this meeting was deliber ated aimed at the younger community and their contributions. As a conse quence, the content of the presentations was refreshingly new, as it should be. In spite of the deficiences caused by the lack of certain key researchers in this field, for one reason or another, the final result was rewarding to all. Although the conference was held in Fall 1996, the contributions contained herein were submitted as late as Spring 1998, thus the content maintains some degree of trendiness. Originally the current volume was to be a "proceedings. " This refers to the usual archival tome that fills one's shelf and is rarely consulted, except to see the canonical group photo, which by the way, we also have. Nevertheless, I wanted something more than that. Although the field is rapidly changing, with so-called facts in a state ofconstant volubility, now is a good time for reflection prior to the commencement ofthe Sloan Survey, presumably the definitive large-scale program of low- to moderate-redshift galaxies in our lifetime."

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.

If standard gravitational theory is correct, then most of the matter in the universe is in an unidentified form which does not emit enough light to have been detected by current instrumentation. This proceedings was devoted to a discussion of the so-called "missing matter" problem in the universe. The goal of the School was to make current research work on unseen matter accessible to students of faculties without prior experience in this area. Due to the pedagogical nature of the School and the strong interactions between students and the lectures, the written lectures included in this volume often contain techniques and explanations not found in more formal journal publications.

If standard gravitational theory is correct, then most of the matter in the universe is in an unidentified form which does not emit enough light to have been detected by current instrumentation. This proceedings was devoted to a discussion of the so-called "missing matter" problem in the universe. The goal of the School was to make current research work on unseen matter accessible to students of faculties without prior experience in this area. Due to the pedagogical nature of the School and the strong interactions between students and the lectures, the written lectures included in this volume often contain techniques and explanations not found in more formal journal publications.

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.

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.

A reconstruction of the Chinese sky of two thousand years ago, based on analysis of the first star catalogue in China and other sources. Presented in six well-sized star maps for 100 BC, it is especially important for the history of astronomy. The Han sky, with five times more constellations than Ptolemy knew, reflects diverse human activities. The way in which constellations were grouped discloses a systematic cosmology, uniting universe and the state.
The work of the three Han schools is comparable to Ptolemy's "Almagest. With three detailed Appendices on the constellations of the three schools, well illustrated to demonstrate the relation between sky and human society, this book is valuable not only for astronomy historians and sinologists, but in general for scholars interested in the ancient cultures of Asia.

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.

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.

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.