Galaxies are vast ensembles of stars, gas and dust, embedded in dark matter halos. They are the basic building blocks of the Universe, gathered in groups, clusters and super-clusters. They exist in many forms, either as spheroids or disks. Classifications, such as the Hubble sequence (based on mass concentration and gas fraction) and the colormagnitude diagram (which separates a blue cloud from a red sequence) help to understand their formation and evolution. Galaxies spend a large part of their lives in the blue cloud, forming stars as spiral or dwarf galaxies. Then, via a mechanism that is still unclear, they stop forming stars and quietly end in the red sequence, as spheroids. This transformation may be due to galaxy interactions, or because of the feedback of active nuclei, through the energy released by their central super-massive black holes. These mechanisms could explain the history of cosmic star formation, the rate of which was far greater in the first half of the Universe s life. Galaxies delves into all of these surrounding subjects in six chapters written by dedicated, specialist astronomers and researchers in the field, from their numerical simulations to their evolutions.

This thesis presents an in-depth, high-resolution observational study on the very beginning of the formation process: the fragmentation of dense molecular clouds known as infrared dark clouds (IRDCs). Using the Submillimeter Array (SMA) and Very Large Array (VLA) radio interferometers, the author has discovered a common picture of hierarchical fragmentation that challenges some of the leading theoretical models and suggests a new, observation-driven understanding of how massive star formation in clustered environments may begin: it is initiated by the hierarchical fragmentation of a dense filament from 10 pc down to 0.01 pc, and the stellar mass buildup is simultaneously fed by hierarchical accretion at similar scales. The new scenario points out the importance of turbulence and filamentary structure, which are now receiving increasing attention and further tests from both observers and theorists.

Set against the background of beautiful Mirabello Bay, astronomers from fourteen countries met at Elounda, Crete in the period 7-18June, 1999 to debate some of the most compelling issues of present day astrophysics. Neutron stars and black holes have been at the forefront of astrophysics for over thirty years. As recently as ten years ago it was still being debated whether galactic stellar-mass black holes existed or not.It is now generally accepted that many (possibly a thousand) stellar-mass black holes - most of them still undetected - lie in low mass X-ray binary (LMXB) systems; a few of them are detected every year as X-ray or gamma-ray transients. These objects are more massive than 3 M, the maximum possible mass 0 for a neutron star, and show none of the tell-tale signs of neutron stars, such as X-ray bursts and X-ray pulsations. It is quite remarkable that all LMXBs display a similar temporal and spectral behaviour, 'independently of whether the accreting compact object is a neutron star or a black hole. A broad debate on these similarities and differences naturally constituted one of the main focal points during the Elounda meeting. Evidence on these aspects has been forthcoming from the Compton Gamma-ray Observatory (CGRO), the ROSAT and ASCA satellites, the Rossi X-Ray Timing Explorer (RXTE), and from the Beppo SAX Observatory."

Proceedings of the Midnight Sun Conference, held in Tromso, Norway, July 1-8, 1987"

Presents an entertaining and accessible approach whilst also providing a rigorous and comprehensive presentation of the subject. Describes how to unveil the ages of stellar populations in distant galaxies that we cannot resolve into individual stars. Contains historical notes about these techniques, outstanding major problems, and a discussion on future developments in the field.

Presents an entertaining and accessible approach whilst also providing a rigorous and comprehensive presentation of the subject. Describes how to unveil the ages of stellar populations in distant galaxies that we cannot resolve into individual stars. Contains historical notes about these techniques, outstanding major problems, and a discussion on future developments in the field.

The previous Saas-Fee Advanced Course dedicated to the interstellar medium took place in 1972. The tremendous scientific advances that have occurred in this field since then, in particular owing to the availabihty of receivers working at completely unexplored wavelength bands, fuUy justified a new set of lectures. As a consequence, the members of the Swiss Society for Astrophysics and As tronomy voted that "The Galactic Interstellar Medium" should be the subject of the 1991 course. The 21st Saas Fee Advanced Course took place in Les Diablerets from 18 to 23 March 1991, gathering together about 80 participants from all over the world, but mostly from Europe. According to a rule that has proved to lead to success, but also to chal lenge the lecturers' energy, the format of a Saas-Fee Advanced Course consists traditionally of 28 lectures of 45 minutes which take place in the morning and late afternoon, leaving ample time for discussions, self-study, hiking or skiing. Despite the inordinate work load imposed, this year's lecturers felt that the subject was sufficiently dense to increase the lecture time by 1/3! This proved judicious and left more time for questions and discussions during the lectures.

It is the stars, The stars above us, govern our conditions. William Shakespeare, King Lear A Few Words about What, Why and How The structure of the stars in general, and the Sun in particular, has been the subject of extensivescienti?cresearchanddebateforoveracentury.Thediscoveryofquantum theoryduringthe?rsthalfofthenineteenthcenturyprovidedmuchofthetheoretical background needed to understand the making of the stars and how they live off their energysource. Progress in the theoryof stellar structurewasmade through extensive discussions and controversies between the giants of the ?elds, as well as brilliant discoveries by astronomers. In this book, we shall carefully expose the building of the theory of stellar structure and evolution, and explain how our understanding of the stars has emerged from this background of incessant debate. About hundred years were required for astrophysics to answer the crucial ques tions: What is the energy source of the stars? How are the stars made? How do they evolve and eventually die? The answers to these questions have profound im plications for astrophysics, physics, and biology, and the question of how we our selves come to be here. While we already possess many of the answers, the theory of stellar structure is far from being complete, and there are many open questions, for example, concerning the mechanisms which trigger giant supernova explosions. Many internal hydrodynamic processes remain a mystery. Yet some global pictures can indeed be outlined, and this is what we shall attempt to do here.

In 1965 Fritz Zwicky proposed a class of supernovae that he called "Type V", described as "excessively faint at maximum". There were only two members, SN1961v and Eta Carinae. We now know that Eta Carinae was not a true supernova, but if it were observed today in a distant galaxy we would call it a "supernova impostor". 170 years ago it experienced a "great eruption" lasting 20 years, expelling 10 solar masses or more, and survived. Eta Carinae is now acknowledged as the most massive, most luminous star in our region of the Galaxy, and it may be our only example of a very massive star in a pre-supernova state. In this book the editors and contributing authors review its remarkable history, physical state of the star and its ejecta, and its continuing instability. Chapters also include its relation to other massive, unstable stars, the massive star progenitors of supernovae, and the "first" stars in the Universe.

This book provides an accessible introduction to the fascinating and topical subject of black holes. It bridges the gap between popular non-mathematical expositions and advanced research texts, using simple undergraduate level calculations and the most basic knowledge of relativity to explain current research. This means the theory can be understood by a wide audience of physicists, including those who are not necessarily interested in learning higher-level mathematical techniques.The third edition links more of the current research trends to fundamental aspects of the physics of black holes. Additionally: This new edition introduces a chapter dedicated to a selection of recent results. Existing chapters have been updated and new explanatory material has been added to aid in the understanding of the physics.This book is recommended reading for advanced undergraduate students and first-year postgraduates who will find it a useful stepping-stone to the advanced literature.

7 Hydrodynamic Instabilities in Close Binary Systems (Frederic A. Rasio) 121 7. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . 121 7. 1. 1 The stability of self-gravitating fluid equilibria 121 7. 1. 2 Astrophysical motivation . 123 7. 1. 3 Common envelope systems 125 7. 2 Dynamical instabilities. . . . . . . 126 7. 2. 1 Physical mechanism . . . . 126 7. 2. 2 Application to coalescing neutron star binaries 127 7. 3 Secular instabilities. . . . . . . . . . . 130 7. 3. 1 Physical mechanism . . . . . . 130 7. 3. 2 Application to contact binaries 133 8 Common Envelope Evolution in Binary Systems (Mario Livio) 141 8. 1 Introduction. . . . . . . . . . . . . . . . . . . . 141 8. 2 The entrance into the common envelope phase . . . . . 142 8. 3 The outcome of the CE phase. . . . . . . . . . . . . . . 145 8. 4 How close can we get to observing the common envelope Phase? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 8. 4. 1 How can PNe with binary nuclei be used to constrain CE physics . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 8. 4. 2 How can nova systems be used to constrain CE physics 148 8. 4. 3 Other tests of common envelope evolution 150 8. 5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . 151 9 Structure and Evolution of Massive Close Binaries (Dany Vanbeveren) 155 9. 1 Introduction. . . . . . . . . . . . . . . . . . 155 9. 2 Definitions. . . . . . . . . . . . . . . . . . . 156 9. 3 Intermediate mass and massive single stars 156 9. 3. 1 Observations . . . . . . . . . . . . . 156 9. 3. 2 Stellar structure equations for non-rotating IMS's and MS's 160 9. 3. 3 Evolutionary computations of non-rotating IMS's and MS's 162 9. 3. 4 Overall comparison with observations '" 163 9. 3. 5 The role of rotation in single star evolution . . .

The first Asia-Pacific Conference on Few-Body Problems in Physics took place from August 23 to August 28, 1999, at the Noda campus of the Sci ence University of Tokyo in Noda-city and Sawayaka Chiba Kenmin Plaza in Kashiwa-city, a suburb of Tokyo close to the Narita-Tokyo International Air port, with the Frontier Research Center for Computation Sciences (FRCCS) of the Science University of Tokyo as the host institute. The High Energy Accel erator Research Organization (KEK), the Institute of Physical and Chemical Research (RIKEN), the Research Center for Nuclear Physics (RCNP)-Osaka University, the Physical Society of Japan, and the Association of Asia Pacific Physical Societies (AAPPS) supported this conference. The conference was initiated in the Asia Pacific area as a counterpart to the successful European Conference on Few-Body Problems in Physics (APFB99), in addition to the International Few-Body Conference Series and the Few Body Gordon Conference series in North America. The Physics of Few-Body Problems covers, as is well known, systems with finite numbers of particles in contrast to many-body systems with very large numbers of particles. Therefore, it covers such wide fields as mesoscopic, atom-molecular, exotic atom, nucleon, hyperon, and quark-gluon physics, plus their applications."

Proceedings of IAU Symposium No. 53 held in Boulder, Colorado, 21-26 August 1972

Supernovae are among the most exciting things occurring in the universe. Much recent research has concentrated on phenomena related to supernovae. For example, the origin of the cosmic rays and the origin of the bulk of the heavy elements seem to be closely associated with the phenomenon of supernovae. With the discovery of the pulsar in the Crab, it seemed clear that supernovae were also intimately as sociated with the formation of neutron stars and perhaps even black holes. The purpose of the conference, of which this volume contains the proceedings, was to bring together the leaders of supernova re search, each of whom has concentrated on different aspects of the problem, to try to form a coherent picture both observationally and theoretically of our current understanding of supernovae. In so doing, key invited talks were presented on the light curves of super novae, both observationally and theoretically; on the possible uses of supernovae, for example in determination of the Hubble Constant; on the formation and evolution of supernova remnants, again both ob servationally and theoretically. The possibility that supernovae might explain quasars was also presented. A review of the current status of statistics of supernovae was presented, giving the rate at which they go off and the implications with regard to what mass stars are the progenitors for supernovae. Again, this was presented both from the observational point of view and from the theoretical stellar evolution point of view."

Metal-rich stars accumulate their metals from previous generations of stars, and so contain the history of their galaxy. By studying these stars we can gain valuable insights into how metals change the formation and evolution of stars, and explain the extraordinary massive star populations observed in the metal-rich region of our own galaxy. Recent observations of metal-rich regions have shown that stars hosting giant planets are generally metal-rich, which has triggered further observations of metal-rich stars. This has led to the discovery of new exoplanets, and advances in the study of planet formation and the late chemical evolution of galaxies. This book is the first on this topic, and it covers many aspects, from spectral line formation to stellar formation and evolution in high metallicity regimes. It is invaluable to researchers and graduate students in stellar evolution, extragalactic astronomy, and planet formation.

The book begins with a historical introduction, "Star Formation: The Early History", that presents new material of interest for students and historians of science. This is followed by two long articles on "Pre-Main-Sequence Evolution of Stars and Young Clusters" and "Observations of Young Stellar Objects". These articles on the fascinating problem of star formation from interstellar matter give a thorough overview of present-day theories and observations. The articles contain material so far unpublished in the astronomical literature. The book addresses graduate students and can be used as a textbook for advanced courses in stellar astrophysics.

IAU Symposium No. 80, The HR Diagram - The 100th Anniversary of Henry Norris Russell was held on November 2-5, 1977 at the National Academy of Sciences in Washington D. C. , in order to commemmorate the birth of Henry Norris Russell on October 25, 1877 and to review current problems in the use of the Hertzsprung-Russell diagram. The IAU has sponsored two previous conferences concerned mainly with the HR diagram; The Position of Variable Stars in the Hertzsprung-Russell Diagram, a colloquium held at Bamberg in 1965 and The Hertzsprung Russell Diagram (IAU Symposium No. 10, J. L. Greenstein, ed. ) held in Moscow in 1959. In 1974 a conference, Multicolor Photometry and the Theoretical HR Diagram (Dudley Obs. Report No. 9, A. G. D. Philip and D. S. Hayes, eds. ) was held in Albany, N. Y. ; and in 1964 a conference, Basic Data Pertaining to the Hertzsprung-Russell Diagram, was held at the Flagstaff Station of the U. S. Naval Observatory in honor of Ejnar Hertzsprung and to dedicate the 61-inch astrometric reflector. (Vistas in Astronomy Vol. ~, A. Beer and K. Aa. Strand, eds. , Pergamon Press, Oxford). Volume 12 of Vistas in Astronomy, The Henry Norris Russell Memorial Volume (1970), contains a review paper on Changing Interpretations of the Hertzsprung-Russell Diagram 1910-1940, A Historical Note by B. W. Sitterly.

Black holes are becoming increasingly important in contemporary research in astrophysics, cosmology, theoretical physics, and mathematics. Indeed, they provoke some of the most fascinating questions in fundamental physics, which may lead to revolutions in scientific thought. Written by distinguished scientists, Classical and Quantum Black Holes provides a comprehensive panorama of black hole physics and mathematics from a modern point of view. The book begins with a general introduction, followed by five parts that cover several modern aspects of the subject, ranging from the observational and the experimental to the more theoretical and mathematical issues. The material is written at a level suitable for postgraduate students entering the field.

Loyal readers of the monthly "Universe" essays in Natural History magazine have long recognized Neil deGrasse Tyson's talent for guiding them through the mysteries of the cosmos with clarity and enthusiasm. Bringing together more than forty of Tyson's favorite essays, ?Death by Black Hole? explores a myriad of cosmic topics, from what it would be like to be inside a black hole to the movie industry's feeble efforts to get its night skies right. One of America's best-known astrophysicists, Tyson is a natural teacher who simplifies the complexities of astrophysics while sharing his infectious fascination for our universe.

On March 28 and 29, 1969, at the occasion of the dedication of the European Southern Observatory, some 90 astronomers from all over the world gathered at the ESO headquarters at Santiago de Chile for discussing problems of the Magellanic Clouds. They came from Argentina, Australia, Chile, Mexico, South Mrica and the United States as well as from Europe; these latter, naturally, mostly from the member states ofESO. The choice of the subject was an obvious one. When erecting the European Southern Observatory as a joint effort in European astronomy, it was agreed from the beginning that the field of research should be the southern sky, so far hardly explored with large telescopes. Among the objects to be investigated, the Magellanic Clouds rank highest, together with the galactic centre region and the southern spiral structure. Being located ten times closer than the nearest large stellar systems accessible to northern observers, and containing a stellar population ranging in age from the oldest down of star formation, the Clouds provide an ideal laboratory for research on to the stage current problems in astrophysics. Yet, most of the northern observational astronomers were hardly acquainted with the Magellanic Clouds; naturally, they are used to think in terms of research projects that can be conducted at their observatories. A survey of the status of knowledge and research on the Clouds therefore appeared in order now that the first- medium size- telescopes of ESO came into operation.

It is well known that stellar winds are variable, and the fluctuations are often cyclical in nature. This property seems to be shared by the winds of cool and hot stars, even though their outflows are driven by fundamentally different physical mechanisms. Since very similar models have been proposed to explain the cyclical wind variations observed in a wide variety of stars, the time was ripe for astrophysicists from many different sub-disciplines to present the state of the art in a concise form. The proceedings will provide a useful, up-to-date overview of the observations, interpretation, and modelling of the time-dependent mass outflows from all sorts of stars.

'A paean to the beauty and majesty of nature, especially the nature we overlook in our back gardens and local parks... And like all the best books, it makes the world around you a lot more interesting' - Spectator 'Beautifully written... I promise you will feel more in tune with the world around after reading only one chapter of Wild Signs and Star Paths, let alone the book in its entirety' - Royal Institute of Navigation 'A beautifully written almanac of tricks and tips that we've lost along the way' - Observer Tristan Gooley, author of the internationally bestselling How To Read Water and The Walker's Guide to Outdoor Clues & Signs, shows how it is possible to achieve a level of outdoors awareness that will enable you to sense direction from stars and plants, forecast weather from woodland sounds and predict the next action of an animal from its body language - instantly. Although once common, this now rare awareness would be labelled by many as a 'sixth sense'. We have become so distanced from this way of experiencing our environment that it may initially seem hard to believe that it is possible, but Tristan Gooley uses a collection of 'keys' to show how everyone can develop this ability and enjoy the outdoors in an exciting way - one that is both new and ancient.

Galaxies have a history. This has become clear from recent sky surveys, which have shown that distant galaxies, formed early in the life of the Universe, differ from the nearby ones. New observational windows at ultraviolet, infrared and millimetric wavelengths (provided by ROSAT, IRAM, IUE, IRAS, ISO) have revealed that galaxies contain a wealth of components: very hot gas, atomic hydrogen, molecules, dust, dark matter. A significant advance is expected due to new instruments (VLT, FIRST, XMM) which will allow one to explore the most distant Universe. Three Euroconferences have been planned to punctuate this new epoch in galactic research, bringing together specialists in various fields of Astronomy. The first, held in Granada (Spain) in May 2000, addressed the observational clues. The second will take place in October 2001 in St Denis de la Reunion (France) and will review the basic building blocks and small-scale processes in galaxy evolution. The third will take place in July 2002 in Kiel (Germany) and will be devoted to the overall modelling of galaxy evolution. This book contains the proceedings of the first conference. It is recommended to researchers and PhD students in Astrophysics."