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.

Our view of the Galaxy has recently been undergoing an increasing divergence from the traditional standpoint. In this book, ten authors discuss in eight chapters how the conceptions of the Milky Way have moved in new directions. Starting with the inner parsec and the Centre of the Galaxy, the book gradually moves on to the bulge and its relation to the globular clusters and to the disk, of which the presence of a bar is argued. A new look on the HI distribution in the disk, a synthesis of molecular line surveys and the study of stellar populations are discussed in the last three chapters.

The New General Catalogue (NCG), originally created in 1888, is the source for referencing bright nebulae and star clusters, both in professional and amateur astronomy. With 7840 entries, it is the most-used historical catalogue of observational astronomy, and NGC numbers are commonly used today. However, the fascinating history of the discovery, observation, description and cataloguing of nebulae and star clusters in the nineteenth century has largely gone untold, until now. This well-researched book is the first comprehensive historical study of the NGC, and is an important resource to all those with an interest in the history of modern astronomy and visual deep-sky observing. It covers the people, observatories, instruments and methods involved in nineteenth-century visual deep-sky observing, as well as prominent deep-sky objects. The book also compares the NGC to modern object data, demonstrating how important the NGC is in observational astronomy today.

'Athena seized the writhing serpent and hurled it into the sky, and fixed it to the very pole of the heavens.' The constellations we recognize today were first mapped by the ancient Greeks, who arranged the stars into patterns for that purpose. In the third century BC Eratosthenes compiled a handbook of astral mythology in which the constellations were associated with figures from legend, and myths were provided to explain how each person, creature, or object came to be placed in the sky. Thus we can see Heracles killing the Dragon, and Perseus slaying the sea-monster to save Andromeda; Orion chases the seven maidens transformed by Zeus into the Pleiades, and Aries, the golden ram, is identified flying up to the heavens. This translation brings together the later summaries from Eratosthenes' lost handbook with a guide to astronomy compiled by Hyginus, librarian to Augustus. Together with Aratus's astronomical poem the Phaenomena, these texts provide a complete collection of Greek astral myths; imaginative and picturesque, they also offer an intriguing insight into ancient science and culture. ABOUT THE SERIES: For over 100 years Oxford World's Classics has made available the widest range of literature from around the globe. Each affordable volume reflects Oxford's commitment to scholarship, providing the most accurate text plus a wealth of other valuable features, including expert introductions by leading authorities, helpful notes to clarify the text, up-to-date bibliographies for further study, and much more.

The idea of the symposium came during the XVllth General Assembly of the IAU at Montreal. The Working Group on Be stars adopted both the proposal of holding a meeting, and of having it at the Universitats- sternwarte Munich. The meeting was organized under the auspices of IAU Comm. 29 (Stel- lar Spectra) and the sponsorship of Comm. 45 (Stellar Classification). The Scientific Organizing Committee was composed of Mercedes Jaschek (chairman), W. Bonsack, C. de Loore, A. Feinstein, H. G. Groth, P. Harmanec, L. Houziaux, A. M. Hubert-De1p1ace, L. S. Luud, A. Slettebak and A. Underhill. The members of this committee are to be thanked for their devotion to the organization of what turned out to be a very successful meeting. The program was organized on an observational approach, comprising sessions on photometry, polarization, spectroscopy, infrared observations, rotation and binarity, X-ray observations, UV observations and mass loss, and atmospheric models. Each session started with an invited summary paper, followed by a number of contributions. The different sessions were chaired by A. Feinstein, R. Sta1io, C. de Loore, Ch. Fehrenbach, J. P. Swings, C. Jaschek, A. Sapar, G. T. Traving, M. de Groot and H. G. Groth. Upon request of the Working Group., a special session was devoted to bibliographic problems and observing campaigns. The Dean of the Faculty for Physics 0.GBP the Ludwig-Maximilians-, Universitat welcomed the participants at the beginning of the Symposium. The meeting was closed by a summary talk, delivered by ~. P. Snow.

Originally published in 1957, this book contains twenty-three contributions from a symposium held during the Ninth General Assembly of the International Astronomical Union in Dublin. The papers contained range from present knowledge in stellar instability to the presentation of new research results and focus on the instability among the hot stars of both low and high luminosity and the cool stars and their close binary systems. Papers range from 'Physical processes in novae' to 'Variable stars and problems of stellar formation' to 'Photometric evidence of instability in eclipsing systems'. Accounts of discussion, which followed the presentations, are also included for reference as well as photographs and diagrams. Offering a re-assessment of non-stable stars and recognising, relocating and redefining the issues surrounding stellar instability, this book will be a valuable reference work to anyone interested in the history of physics, astronomy and cosmology.

This book introduces an analytic method to describe the shadow of black holes. As an introduction, it presents a survey of the attempts to observe the shadow of galactic black holes. Based on a detailed discussion of the Plebanski-Demianski class of space-times, the book derives analytical formulas for the photon regions and for the boundary curve of the shadow as seen by an observer in the domain of outer communication. It also analyzes how the shadow depends on the motion of the observer. For all cases, the photon regions and shadows are visualized for various values of the parameters. Finally, it considers how the analytical formulas can be used for calculating the horizontal and vertical angular diameters of the shadow, and estimates values for the black holes at the centers of our Galaxy near Sgr A* and of the neighboring galaxy M87.

Summarising the striking advances of the last two decades, this reliable introduction to modern astronomical polarimetry provides a comprehensive review of state-of-the-art techniques, models and research methods. Focusing on optical and near-infrared wavelengths, each detailed, up-to-date chapter addresses a different facet of recent innovations, including new instrumentation, techniques and theories; new methods based on laboratory studies, enabling the modelling of polarimetric characteristics for a wide variety of astronomical objects; emerging fields of polarimetric exploration, including proto-planetary and debris discs, icy satellites, transneptunian objects, exoplanets, and the search for extraterrestrial life; and unique results produced by space telescopes, and polarimeters aboard exploratory spacecraft. With contributions from an international team of accomplished researchers, this is an ideal resource for astronomers and researchers working in astrophysics, earth sciences, and remote sensing keen to learn more about this valuable diagnostic tool. The book is dedicated to the memory of renowned polarimetrist Tom Gehrels.

Guiding the reader through all the stages that lead to the formation of a star such as our Sun, this advanced textbook provides students with a complete overview of star formation. It examines the underlying physical processes that govern the evolution from a molecular cloud core to a main-sequence star, and focuses on the formation of solar-mass stars. Each chapter combines theory and observation, helping readers to connect with and understand the theory behind star formation. Beginning with an explanation of the interstellar medium and molecular clouds as sites of star formation, subsequent chapters address the building of typical stars and the formation of high-mass stars, concluding with a discussion of the by-products and consequences of star formation. This is a unique, self-contained text with sufficient background information for self-study, and is ideal for students and professional researchers alike.

An Astronomical Life - Observing the Depths of the Universe" Though science as a subject can be di?cult, what has been more important for me is that its practice can also be rewarding fun! This book is crafted to expose the reader to the excitement of modern observational cosmology through the study of galaxy evolution over space and cosmic time. Recent extragalactic research has led to many rapid advances in the ?eld. Even a suitable skeptic of certain pronouncements about the age and structure of the Universe should be pleased with the large steps that have been taken in furthering our understanding of the Universe since the early 1990's. My personal involvement in galaxy research goes back to the 1960's. At that point, galaxies were easily recognized and partially understood as organized c- lections of stars and gas. What their masses were presented a problem, which I supposed would just fade away. But fade it didn't. Distant active nuclei and quasars were discovered in the mid-1960's. A c- mon view of QSOs was that they have large redshifts, but what use are they for cosmology or normal galaxy astrophysics? I shared that conclusion. My expec- tions fell below their potential utility. In short, the Universe of our expectations rarely matches the Universe as it is discovered.

This brief brings together the theoretical aspects of star formation and ionized regions with the most up-to-date simulations and observations. Beginning with the basic theory of star formation, the physics of expanding HII regions is reviewed in detail and a discussion on how a massive star can give birth to tens or hundreds of other stars follows. The theoretical description of star formation is shown in simplified and state-of-the-art numerical simulations, describing in a more clear way how feedback from massive stars can trigger star and planet formation. This is also combined with spectacular images of nebulae taken by talented amateur astronomers. The latter is very likely to stimulate the reader to observe the structure of nebulae from a different point of view, and better understand the associated star formation therein.

This book presents the status of research on very massive stars in the Universe. While it has been claimed that stars with over 100 solar masses existed in the very early Universe, recent studies have also discussed the existence and deaths of stars up to 300 solar masses in the local Universe. This represents a paradigm shift for the stellar upper-mass limit, which may have major implications far beyond the field of stellar physics. The book comprises 7 chapters, which describe this discipline and provide sufficient background and introductory content for graduate (PhD) students and researchers from different branches of astronomy to be able to enter this exciting new field of very massive stars.

From supernovae and gamma-ray bursts to the accelerating Universe, this is an exploration of the intellectual threads that lead to some of the most exciting ideas in modern astrophysics and cosmology. This fully updated second edition incorporates new material on binary stars, black holes, gamma-ray bursts, worm-holes, quantum gravity and string theory. It covers the origins of stars and their evolution, the mechanisms responsible for supernovae, and their progeny, neutron stars and black holes. It examines the theoretical ideas behind black holes and their manifestation in observational astronomy and presents neutron stars in all their variety known today. This book also covers the physics of the twentieth century, discussing quantum theory and Einstein's gravity, how these two theories collide, and the prospects for their reconciliation in the twenty-first century. This will be essential reading for undergraduate students in astronomy and astrophysics, and an excellent, accessible introduction for a wider audience.

Gerald North's complete practical guide and resource package instructs amateur astronomers in observing and monitoring variable stars and other objects of variable brightness. Descriptions of the objects are accompanied by explanations of the background astrophysics, providing readers with real insight into what they are observing at the telescope. The main instrumental requirements for observing and estimating the brightness of objects by visual means and by CCD photometry are detailed, and there is advice on the selection of equipment. The book contains a CD-ROM packed with resources, including hundreds of light-curves and over 600 printable finder charts. Containing extensive practical advice, this comprehensive guide is an invaluable resource for amateur astronomers of all levels, from novices to more advanced observers. Gerald North is a lifelong amateur astronomer. In addition to being a member of the British Astronomical Association since 1977, he is also the author of many books, including Advanced Amateur Astronomy (Cambridge, 1997) and Observing the Moon (Cambridge, 2000).

Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

In this approachable and fascinating biography of the galaxy, an astrophysicist and folklorist details everything humans have discovered—from the Milky Way's formation to its eventual death, and what else there is to learn about the universe we call home.

After a few billion years of bearing witness to life on Earth, of watching one hundred billion humans go about their day-to-day lives, of feeling unbelievably lonely, and of hearing its own story told by others, The Milky Way would like a chance to speak for itself. All one hundred billion stars and fifty undecillion tons of gas of it.

It all began some thirteen billion years ago, when clouds of gas scattered through the universe's primordial plasma just could not keep their metaphorical hands off each other. They succumbed to their gravitational attraction, and the galaxy we know as the Milky Way was born. Since then, the galaxy has watched as dark energy pushed away its first friends, as humans mythologized its name and purpose, and as galactic archaeologists have worked to determine its true age (rude). The Milky Way has absorbed supermassive (an actual technical term) black holes, made enemies of a few galactic neighbors, and mourned the deaths of countless stars. Our home galaxy has even fallen in love.

After all this time, the Milky Way finally feels that it's amassed enough experience for the juicy tell-all we've all been waiting for. Its fascinating autobiography recounts the history and future of the universe in accessible but scientific detail, presenting a summary of human astronomical knowledge thus far that is unquestionably out of this world.

This thesis presents a study of the origin of an apparently extended X-ray emission associated with the Galactic ridge. The study was carried out with broadband spectra obtained from mapping observations in the Galactic bulge region conducted in 2005-2010 by the Suzaku space X-ray observatory. The spectra were analyzed with a newly constructed X-ray spectral model of an accreting white dwarf binary that is one of the proposed candidate stars for the origin of the Galactic ridge emission in the higher energy band. Fitting of the observed Galactic ridge spectra with the model showed that there is another spectral component that fills the gap between the observed X-ray flux and the component expected from the accreting white dwarf spectral model in the lower energy band. This additional soft spectral component was nicely explained by an X-ray spectral model of normal stars. The result, together with previously reported high-resolution imaging results, strongly supports the idea that the Galactic ridge X-ray emission is an assembly of dim, discrete X-ray point sources.

First published in 1986, this is the story of the analysis of starlight by astronomical spectroscopy. Beginning with Joseph Fraunhofer's discovery of spectral lines in the early nineteenth century, this new edition continues the story through to the year 2000. In addition to the key discoveries, it presents the cultural and social history of stellar astrophysics by introducing the leading astronomers and their struggles, triumphs and disagreements. Basic concepts in spectroscopy and spectral analysis are included, so both observational and theoretical aspects are described, in a non-mathematical framework. This new edition covers the final decades of the twentieth century, with its major advances in stellar astrophysics: the discovery of extrasolar planets, new classes of stars and the observation of the ultraviolet spectra of stars from satellites. The in-depth coverage makes it essential reading for graduate students working in stellar spectroscopy, professional and amateur astronomers, and historians of science.

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.

This thesis represents the first wide-field photometric and spectroscopic survey of star clusters in the nearby late-spiral galaxy M33. This system is the nearest example of a dwarf spiral galaxy, which may have a unique role in the process of galaxy formation and evolution. The cold dark matter paradigm of galaxy formation envisions large spiral galaxies, such as the Milky Way, being formed from the merger and accretion of many smaller dwarf galaxies. The role that dwarf spiral galaxies play in this process is largely unclear. One of the goals of this thesis is to use the star cluster population of M33 to study its formation and evolution from its early stages to the present. The thesis presents a new comprehensive catalog of M33 star clusters, which includes magnitudes, colors, structural parameters, and several preliminary velocity measurements. Based on an analysis of these data, the thesis concludes that, among other things, the evolution of M33 has likely been influenced by its nearby massive neighbor M31.

The mapping of the surface of stars requires diverse skills, analysis techniques and advanced modeling, i.e. the collaboration of scientists in various specialties. This volume gives insights into new techniques allowing for the first time to obtain resolved images of stars. It takes stock of what has been achieved so far in Chile, on the ESO VLTI instrument or, in the States, on the CHARA instrument. In recent times interferometry, combined with adaptive optics has allowed to reconstruct images of stars. Besides the Sun (of course) by now five stars have been resolved in detail. In addition to interferometry, this book highlights techniques used for mapping the surfaces of stars using photometry made by space observatories; Zeeman- and Doppler Imaging; mapping the surface element abundances via spectroscopy. This book will also take stock of the best images of the solar surface, made by connecting the differential rotation to the underlying physical parameters derived from helioseismology. Recent measurements of flattening of the solar surface by SDO showed that the Sun's shape is linked to the rotation of the core. It is shown how such a result is generalizable to the stars.

The proceedings of the Second European Meeting on "New Aspects of MagellanicCloud Research" review the most recent progress in the study of the LMC and SMC. The activities within the ground-based ESO key programme "Coordinated Investigations of Selected Regions in the Magellanic Clouds", as well as new exciting observations from space missions (ROSAT, IUE, ISO, IRAS) result in a more profound insightinto the structure, kinematics, populations (stars, clusters, interstellar medium), and the chemical composition and evolution of the Magellanic Cloud system. The book addresses researchers and graduate students in astrophysics.

The masses of neutron stars are limited by an instability to gravitational collapse and an instability driven by gravitational waves limits their spin. Their oscillations are relevant to x-ray observations of accreting binaries and to gravitational wave observations of neutron stars formed during the coalescence of double neutron-star systems. This volume includes more than forty years of research to provide graduate students and researchers in astrophysics, gravitational physics and astronomy with the first self-contained treatment of the structure, stability and oscillations of rotating neutron stars. This monograph treats the equations of stellar equilibrium; key approximations, including slow rotation and perturbations of spherical and rotating stars; stability theory and its applications, from convective stability to the r-mode instability; and numerical methods for computing equilibrium configurations and the nonlinear evolution of their oscillations. The presentation of fundamental equations, results and applications is accessible to readers who do not need the detailed derivations.

Proceedings of the 119th Symposium of the International Astronomical Union, held in Bangalore, India, December 2-6, 1985

Proceedings of International Meeting held in Trieste, Italy, April 10-13, 1985