Proceedings of IAU Symposium No. 58 held in Canberra, Australia, August 12-15, 1973

Clusters and superclusters of galaxies are the largest objects in the Universe and are the subject of intense observational study at a variety of wavelengths, from radio to X-ray which has provoked much theoretical debate and advanced the understanding of the recent evolution of the large-scale structure the universe. The subject is reviewed in this volume by researchers who lectured at a NATO Advanced Study Institute held in Cambridge in July 1991. Much of the material is presented in a pedagogical manner and should be useful to scientists, astronomers and graduate students interested in extragalactic astronomy.

'Galactic Radio Astronomy' was chosen as the subject of this Symposium, which was held in conjunction with the IAU General Assembly that took place in Sydney in August 1973, largely because it is a very suitable Southern Hemisphere topic. This results in part from the advantages of a southern location in studying the Galaxy and in part from the long association of Australia with radio astronomy. Following the General Assembly, the Symposium was held at the Surf air Inter national Hotel in Maroochydore, Queensland, from 3 to 7 September, 1973. The conference participants were effectively isolated from the rest of the world during the Symposium, and the excellent spring weather and geographical situation led to the development of an unusually good rapport. The Symposium was sponsored by Commissions 40, 33, and 34. The Organizing Committee was composed of A. H. Barrett (chairman), J. E. Baldwin, D. S. Heeschen, F. J. Kerr, J. Lequeux, S. W. McCuskey, P. G. Mezger, B. Y. Mills, Yu. N. Parijskij, B. J. Robinson, H. van der Laan, and H. F. Weaver. The Local Committee, consisting ofB. J. Robinson, N. G. Seddon, and P. J. Kelly, looked after the arrangements in very fine style. The Symposium was supported financially by the IAU, the Australian Academy o Science, the CSIRO Division of Radiophysics, Union Carbide Australia Limited, and the Science Foundation for Physics within the University of Sydney."

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

In connection with arranging IAU Symposium No. 50 on 'Spectral Classification and Multicolour Photometry', sponsored by Commissions 45 and 25, it was decided to exclude all calibration problems. Instead it was agreed that we should attempt to arrange a separate symposium, dealing with the fundamental problems of the cali bration of absolute magnitudes and temperatures of stars. The Executive Committee of the IAU accepted our proposal, and IAU Symposium No. 54 was held in Geneva on September 12-15, 1972, sponsored by thefollowing IAU Commissions: 24, 25, 29, 33, 35, 37,44 and 45. It was attended by about 90 scientists representing 16 countries. The Symposium was divided into eight sessions. Each session started with a review paper by an invited speaker; this was followed by a general discussion including a few contributed papers. The contents of the present volume follow closely the programmes of the individual sessions of the Symposium. Most of the recorded discussions have been kept, and only in a few cases have the order of questions and comments been altered so as to obtain more homogeneity in the presentation."

The proposal to organize a Symposium on circumstellar matter and extended atmo spheres in binary systems was first made by the Dominion Astrophysical Observatory to the Executive Committee of the International Astronomical Union in the summer of 1969. It received the support of the presidents of Commissions 29 (Stellar Spectra), 30 (Radial Velocities), 36 (Stellar Atmospheres), and 42 (Photometric Double Stars). Approval in principle was given by the Executive Committee almost immediately, and the Committee further suggested that the Symposium be officially designated the Struve Memorial Symposium. Final approval was given at the time of the 1970 General Assembly of the Union. when the dates of the Symposium were set for August or September, 1972. The Organizing Committee set up consisted of K. O. Wright (Chairman), A. H. Batten, K. -H. B6hm, A. A. Boyarchuk, G. Larsson-Leander, and M. Plavec. In addition, J. Sahade and F. B. Wood acted as advisory members. Local organization was entrusted to a committee consisting of A. H. Batten, E. K. Lee, and C. D. Scarfe. The final dates selected were September 6-12, 1972, and the Sym posium was held at the Island Hall Hotel, Parksville, B. C., on Vancouver Island some 90 miles from Victoria. The Organizing Committee attempted to arrange a Symposium of the type in which no contributed papers would be presented and discussion would range as widely as possible over the field covered by the six invited review papers."

We have in this volume, compiled a connected account of the proceedings of the Symposium on Wolf-Rayet and High-Temperature Stars held at Buenos Aires. The Organizing Committee had assigned broad areas of topical interest to be reviewed by invited speakers. Each of these presentations was followed by lengthy discussions that were tape recorded and transcribed later. These discussions have been edited only to a limited extent. We have shortened them and rearranged them to bring about a greater coherence. We have, however, attempted to retain the tenor of the discussions, the flavour of impromptu remarks and the continuity of an argument. Much of the success of such a venture depends on the contributors to the discussions. To be able to make these thoughts available to a larger audience has been the task of those re sponsible for the elaborate tape recording of the proceedings. We thank those at the Instituto de Astronomia y Fisica del Espacio for the efficient way in which this re sponsibility has been discharged. Many at Buenos Aires and Kodaikanal have contrib uted efficient assistance to the preparation of this volume and we are deeply indebted for their help. In particular, two amongst these, Nora Martinez and A. M. Batcha have contributed overwhelmingly both to the organization of the symposium and the final preparation of the symposium volume. Financial support for this symposium came from the International Astronomical Union and the Argentine National Research Council."

Featuring detailed commented spectral profiles of more than one hundred astronomical objects, in colour, this spectral guide documents most of the important and spectroscopically observable objects accessible using typical amateur equipment. It allows you to read and interpret the recorded spectra of the main stellar classes, as well as most of the steps from protostars through to the final stages of stellar evolution as planetary nebulae, white dwarfs or the different types of supernovae. It also presents integrated spectra of stellar clusters, galaxies and quasars, and the reference spectra of some terrestrial light sources, for calibration purposes. Whether used as the principal reference for comparing with your recorded spectra or for inspiring independent observing projects, this atlas provides a breathtaking view into our Universe's past. The atlas is accompanied and supplemented by Spectroscopy for Amateur Astronomers, which explains in detail the methods for recording, processing, analysing and interpreting your spectra.

Twinkling in the night sky, stars have inspired wonder and amazement in us since ancient times. They have guided our journeys and inspired our poetry and art, but until recently we have known very little about them. Now, through new instruments and technology, we are learning more about stars every day-from their dusty beginnings in nebulas to their spectacular ends as supernovas. Award-winning science writer Seymour Simon gives you a closer look at the stars.

Celebrating the centenary of George Ellery Hale's discovery of magnetic fields in sunspots, IAU Symposium 273 reviews the recent advances made in the fields of solar and stellar magnetism. Sunspots are responsible for the time-varying properties of the Sun, including the solar irradiance. Combined study of the spots on the Sun and on other stars provides a greater understanding of sunspot formation and behaviour on a long-term basis. On the other hand, stellar observations can be best understood by using detailed properties of the Sun as a reference point. This volume contains reviews and research articles from solar and stellar astronomers on the recent findings of solar and stellar magnetism using observational, theoretical and simulation studies of the Sun and the stars to approach the subject in a unified manner. Its findings are useful to advanced students and researchers in solar and stellar astronomy.

Illustrated with breathtaking images of the Solar System and of the Universe around it, this book explores how the discoveries within the Solar System and of exoplanets far beyond it come together to help us understand the habitability of Earth, and how these findings guide the search for exoplanets that could support life. The author highlights how, within two decades of the discovery of the first planets outside the Solar System in the 1990s, scientists concluded that planets are so common that most stars are orbited by them. The lives of exoplanets and their stars, as of our Solar System and its Sun, are inextricably interwoven. Stars are the seeds around which planets form, and they provide light and warmth for as long as they shine. At the end of their lives, stars expel massive amounts of newly forged elements into deep space, and that ejected material is incorporated into subsequent generations of planets. How do we learn about these distant worlds? What does the exploration of other planets tell us about Earth? Can we find out what the distant future may have in store for us? What do we know about exoworlds and starbirth, and where do migrating hot Jupiters, polluted white dwarfs, and free-roaming nomad planets fit in? And what does all that have to do with the habitability of Earth, the possibility of finding extraterrestrial life, and the operation of the globe-spanning network of the sciences?

The classic account of the structure and evolution of the early universe from Nobel Prize-winning physicist P. J. E. Peebles An instant landmark on its publication, The Large-Scale Structure of the Universe remains the essential introduction to this vital area of research. Written by one of the world's most esteemed theoretical cosmologists, it provides an invaluable historical introduction to the subject, and an enduring overview of key methods, statistical measures, and techniques for dealing with cosmic evolution. With characteristic clarity and insight, P. J. E. Peebles focuses on the largest known structures-galaxy clusters-weighing the empirical evidence of the nature of clustering and the theories of how it evolves in an expanding universe. A must-have reference for students and researchers alike, this edition of The Large-Scale Structure of the Universe introduces a new generation of readers to a classic text in modern cosmology.

With the development of nuclear physics the theory of the stellar interior entered a new phase. Many new investigations have been conducted and the results published in a variety of specialized media. This book brings these results together in a single volume and summarizes the present status of the theory of stellar evolution. Originally published in 1958. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

The sum of centuries of speculation on the probable course of evolution in stars is discussed by one of the world's greatest astronomers, with a full report of his own conclusions, How long stars exist, the relation of their luminosity to their mass, the evolution of a star in relation to the main sequence, the significance of rotation, are among the crucial problems considered. While the discussion is replete with technical detail, sufficient background is included to enable the amateur astronomer or anyone with scientific training to follow the argument. Originally published in 1950. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

'fascinating' Brian Cox This is the story of citizen science. Where once astronomers sat at the controls of giant telescopes in remote locations, praying for clear skies, now they have no need to budge from their desks, as data arrives in their inbox. And what they receive is overwhelming; projects now being built provide more data in a few nights than in the whole of humanity's history of observing the Universe. It's not just astronomy either-dealing with this deluge of data is the major challenge for scientists at CERN, and for biologists who use automated cameras to spy on animals in their natural habitats. Artificial intelligence is one part of the solution-but will it spell the end of human involvement in scientific discovery? No, argues Chris Lintott. We humans still have unique capabilities to bring to bear-our curiosity, our capacity for wonder, and, most importantly, our capacity for surprise. It seems that humans and computers working together do better than computers can on their own. But with so much scientific data, you need a lot of scientists-a crowd, in fact. Lintott found such a crowd in the Zooniverse, the web-based project that allows hundreds of thousands of enthusiastic volunteers to contribute to science. In this book, Lintott describes the exciting discoveries that people all over the world have made, from galaxies to pulsars, exoplanets to moons, and from penguin behaviour to old ship's logs. This approach builds on a long history of so-called 'citizen science', given new power by fast internet and distributed data. Discovery is no longer the remit only of scientists in specialist labs or academics in ivory towers. It's something we can all take part in. As Lintott shows, it's a wonderful way to engage with science, yielding new insights daily. You, too, can help explore the Universe in your lunch hour.

This book provides a comprehensive overview of the history of ideas about the sun and the stars, from antiquity to modern times. Two theoretical astrophysicists who have been active in the field since the early 1960s tell the story in fluent prose. About half of the book covers most of the theoretical research done from 1940 to the close of the twentieth century, a large body of work that has to date been little explored by historians. The first chapter, which outlines the period from about 3000 B.C. to 1700 A.D., shows that at every stage in history human beings have had a particular understanding of the sun and stars, and that this has continually evolved over the centuries. Next the authors systematically address the immense mass of observations astronomy accumulated from the early seventeenth century to the early twentieth. The remaining four chapters examine the history of the field from the physicists perspective, the emphasis being on theoretical work from the mid-1840s to the late 1990s--from thermodynamics to quantum mechanics, from nuclear physics and magnetohydrodynamics to the remarkable advances through to the late 1960s, and finally, to more recent theoretical work. Intended mainly for students and teachers of astronomy, this book will also be a useful reference for practicing astronomers and scientifically curious general readers.

Written in an informal and engaging style, this volume traces the discoveries that led to our understanding of the size and structure of the Milky Way, and the conclusive evidence for a massive black hole at its center. Robert H. Sanders, an astronomer who witnessed many of these developments, describes how we parted the veil of interstellar dust to probe the strange phenomena within. We now know that the most luminous objects in the Universe - quasars and radio galaxies - are powered by massive black holes at their hearts. But how did black holes emerge from being a mathematical peculiarity, a theoretical consequence of Einstein's theory of gravity, to become part of the modern paradigm that explains active galactic nuclei and galaxy evolution in normal galaxies such as the Milky Way? This story, aimed at non-specialist readers and students and historians of astronomy, will both inform and entertain.

Understanding star formation is one of the key fields in present-day astrophysics. This book treats a wide variety of the physical processes involved, as well as the main observational discoveries, with key points being discussed in detail. The current star formation in our galaxy is emphasized, because the most detailed observations are available for this case. The book presents a comparison of the various scenarios for star formation, discusses the basic physics underlying each one, and follows in detail the history of a star from its initial state in the interstellar gas to its becoming a condensed object in equilibrium. Both theoretical and observational evidence to support the validity of the general evolutionary path are presented, and methods for comparing the two are emphasized. The author is a recognized expert in calculations of the evolution of protostars, the structure and evolution of disks, and stellar evolution in general. This book will be of value to graduate students in astronomy and astrophysics as well as to active researchers in the field.

Ongoing studies in mathematical depth, and inferences from helioseismological' observations of the internal solar rotation have shown up the limitations in our knowledge of the solar interior and of our understanding of the solar dynamo, manifested in particular by the sunspot cycle, the Maunder minimum, and solar flares. This second edition retains the identical overall structure as the first edition, but is designed so as to be self-contained with the early chapters presenting the basic physics and mathematics underlying cosmical magnetohydrodynamics, followed by studies of the specific applications appropriate for a book devoted to a central area in astrophysics.
New to this edition:
Chapter 6 gives an account of the present state of dynamo theory in general, and Chapter 8 the applications to the Sun and to other Late-Type' stars with differing rotation rates -- the Solar-Stellar Connection'. The minority of the more massive Early-Type' stars that are observably magnetic are well described by theoblique rotator' model, with a quasi-steady, fossil' magnetic structure frozen' into the highly conducting, non-turbulent envelope. Chapter 9 deals with the considerable progress on the associated theoretical problems.
Chapter 7 contains new material, relevant to both Late- and Early-Type Main Sequence stars, to the evolved Red Giants, and also to contracting pre-Main Sequence stars (Chapter 10}, which show the highest degree of magnetic activity (the magneto-rotational instability, and the magneto-centrifugal winds emitted by the surrounding accretion disk'). In the earlier phases of star formation in molecular clouds (Chapters 11-12), magneto-turbulence' is emerging as the appropriate scenario for the prediction of the mass spectrum of proto-stars, and the associated formation of planetary satellites. Chapter 14 describes developments in the study of the magnetosphere of a pulsar' -- a magnetized neutron star -- consisting of spontaneously generated electron-positron pairs.

This extensively illustrated book presents the astrophysics of galaxies since their beginnings in the early Universe. It has been thoroughly revised to take into account the most recent observational data, and recent discoveries such as dark energy. There are new sections on galaxy clusters, gamma ray bursts and supermassive black holes. The authors explore the basic properties of stars and the Milky Way before working out towards nearby galaxies and the distant Universe. They discuss the structures of galaxies and how galaxies have developed, and relate this to the evolution of the Universe. The book also examines ways of observing galaxies across the whole electromagnetic spectrum, and explores dark matter and its gravitational pull on matter and light. This book is self-contained and includes several homework problems with hints. It is ideal for advanced undergraduate students in astronomy and astrophysics.

Here, one of the world's leading astrophysicists provides the first comprehensive and logically structured overview of the many ideas and discoveries pertaining to the supermassive black hole at the galactic center known as Sagittarius A*. By far the closest galactic nucleus in the universe, Sagittarius A* alone can provide us with a realistic expectation of learning about the physics of strong gravitational fields, and the impact of such fields on the behavior of matter and radiation under severe physical conditions. Its proximity may even provide the opportunity to directly test one of general relativity's most enigmatic predictions--the existence of closed pockets of space-time hidden behind an event horizon.

The plethora of research on Sagittarius A* since its discovery in 1974 has long seemed an interwoven pattern of loose threads. No one has successfully synthesized this growing body of work into a manageable, coherent book both for professional researchers and for students taking courses focusing on black holes and galactic nuclei--until now. With Fulvio Melia's "The Galactic Supermassive Black Hole," readers finally have at their disposal a one-volume crucible of essential ideas, logically streamlined but with thorough references for those wishing to explore the various topics in greater depth.

Massive stars play a crucial role in the Universe: they are important drivers for the photometric and chemical evolution of galaxies; they are sources of important elements, including those necessary for life; and, with their strong winds and supernova explosions, they feed the interstellar medium with momentum and kinetic energy, impacting on the star formation rate. Knowledge of the evolution of massive stars is important not only for stellar physics, but also for probing the evolution of galaxies and their star formation histories throughout cosmic time. This volume provides an introduction to these topics and to the techniques used to investigate the properties of massive stars, including asteroseismology, spectropolarimetry, and interferometry. It highlights synergies between these new techniques and more classical methods, to create a synthetic view of massive stars, leading researchers towards new and innovative solutions to the most topical questions regarding the evolution of massive stars.

Evolution of Stars and Stellar Populations is a comprehensive presentation of the theory of stellar evolution and its application to the study of stellar populations in galaxies. Taking a unique approach to the subject, this self-contained text introduces first the theory of stellar evolution in a clear and accessible manner, with particular emphasis placed on explaining the evolution with time of observable stellar properties, such as luminosities and surface chemical abundances. This is followed by a detailed presentation and discussion of a broad range of related techniques, that are widely applied by researchers in the field to investigate the formation and evolution of galaxies.
This book will be invaluable for undergraduates and graduate students in astronomy and astrophysics, and will also be of interest to researchers working in the field of Galactic, extragalactic astronomy and cosmology.
* comprehensive presentation of stellar evolution theory
* introduces the concept of stellar population and describes "stellar population synthesis" methods to study ages and star formation histories of star clusters and galaxies.
* presents stellar evolution as a tool for investigating the evolution of galaxies and of the universe in general.

This text, written by two leading experts, reviews the historical observations of supernova explosions in our Galaxy over the past two thousand years and discusses modern observations of the remnants of these explosions at radio and other wavelengths.

This text describes the microscopic physics operating in stars and demonstrates how stars respond from formation, through hydrogen-burning phases, up to the onset of helium burning. Intended for beginning graduate students and senior undergraduates with a solid background in physics, it illustrates the intricate interplay between the microscopic physical processes and the stars' macroscopic responses. The volume starts with the gravitationally contracting phase which carries the star from formation to the core hydrogen-burning main sequence, through the main sequence phase, through shell hydrogen-burning phases as a red giant, up to the onset of core helium burning. Particular emphasis is placed on describing the gravothermal responses of stars to nuclear transformations in the interior and energy loss from the surface, responses which express the very essence of stellar evolution. The volume is replete with many illustrations and detailed numerical solutions to prepare the reader to program and calculate evolutionary models.