This thesis by Cole Johnston brings novel insights into the inner workings of young massive stars. By bridging the observational fields of binary stars and asteroseismology this thesis uses state of the art statistical techniques to scrutinise theories of modern stellar astrophysics. Developing upon the commonly used isochrone fitting methodology, the author introduces the idea of isochrone cloud fitting in order to account for the full breadth of physics observed in stars. The author combines this methodology with gravity mode asteroseismic analysis to asses the level of chemical mixing deep within the stellar core in order to determine the star's age and core mass. Wrapped into a robust statistical framework to account for correlations, this methodology is employed to analyse individual stars, multiple systems, and clusters alike to demonstrate that chemical mixing has dramatic impact on stellar structure and evolution.

IAU Symposium No. 111, "Calibration of Fundamental Stellar Quanti- ties", was held at Villa Olmo, Como, Italy, on May 24-29, 1984. Meet- ings held in the past ten years on related topics include: IAU Symposium No. 109, '*Astrometric Techniques", held at the University of Florida in Jan. , 1984, "The MK Process and Stellar Classification", held at the University of Toronto in June, 1983, "Stellar Absolute Energy Distri- butions", an unpublished Joint Meeting (Commissions 25 and 45), held at the General Assembly of the IAU in Patras, Greece in August, 1982, IAU Colloquium No. 62, "Current Techniques in Double and Multiple Star Re- search", held at Northern Arizona University in May, 1981, the ESO Work- fl shop: "Methods of Abundance Determination for Stars , held in Geneva in March, 1980, "Problems of Calibration of Multicolor Photometric Sys tems", held at Dudley Observatory in March, 1979, IAU Colloquium No. 48, "Modern Astrometry", held at the University of Vienna in Sept. , 1978, IAU Colloquium No. 50, "High Angular Resolution Stellar Interferometry" held at the University of Maryland in Aug. , 1978, "Spectral Classifice. - tion of the Future", held at the Vatican in July, 1978 and IAU Sympos- ium No. 72, "Abundance Effects in Classification", held at the Univer- sity of Lausanne in July, 1975. The present meeting was the first to cover the broad range of the calibration of fundamental stellar qU8T". ti- ties in one meeting. Nine commissions of the IAU co-sponsored the meeting.

The search for life in the universe, once the stuff of science fiction, is now a robust worldwide research program with a well-defined roadmap probing both scientific and societal issues. This volume examines the humanistic aspects of astrobiology, systematically discussing the approaches, critical issues, and implications of discovering life beyond Earth. What do the concepts of life and intelligence, culture and civilization, technology and communication mean in a cosmic context? What are the theological and philosophical implications if we find life - and if we do not? Steven J. Dick argues that given recent scientific findings, the discovery of life in some form beyond Earth is likely and so we need to study the possible impacts of such a discovery and formulate policies to deal with them. The remarkable and often surprising results are presented here in a form accessible to disciplines across the sciences, social sciences, and humanities.

Present-day elliptical, spiral and irregular galaxies are large systems made of stars, gas and dark matter. Their properties result from a variety of physical processes that have occurred during the nearly fourteen billion years since the Big Bang. This comprehensive textbook, which bridges the gap between introductory and specialized texts, explains the key physical processes of galaxy formation, from the cosmological recombination of primordial gas to the evolution of the different galaxies that we observe in the Universe today. In a logical sequence, the book introduces cosmology, illustrates the properties of galaxies in the present-day Universe, then explains the physical processes behind galaxy formation in the cosmological context, taking into account the most recent developments in this field. The text ends on how to find distant galaxies with multi-wavelength observations, and how to extract the physical and evolutionary properties based on imaging and spectroscopic data.

All stars are born in groups. The origin of these groups has long been a key question in astronomy, one that interests researchers in star formation, the interstellar medium, and cosmology. This volume summarizes current progress in the field, and includes contributions from both theorists and observers. Star clusters appear with a wide range of properties, and are born in a variety of physical conditions. Yet the key question remains: How do diffuse clouds of gas condense into the collections of luminous objects we call stars? This book will benefit graduate students, newcomers to the field, and also experienced scientists seeking a convenient reference.

This book uses new data from the very low radio frequency telescope LOFAR to analyse the magnetic structure in the giant radio galaxy NGC6251. This analysis reveals that the magnetic field strength in the locality of this giant radio galaxy is an order of magnitude lower than in other comparable systems. Due to the observational limitations associated with capturing such huge astrophysical structures, giant radio galaxies are historically a poorly sampled population of objects; however, their preferential placement in the more rarefied regions of the cosmic web makes them a uniquely important probe of large-scale structures. In particular, the polarisation of the radio emissions from giant radio galaxies is one of the few tools available to us that can be used to measure magnetic fields in regions where the strength of those fields is a key differentiator for competing models of the origin of cosmic magnetism. Low frequency polarisation data are crucial for detailed analyses of magnetic structure, but they are also the most challenging type of observational data to work with. This book presents a beautifully coupled description of the technical and scientific analysis required to extract valuable information from such data and, as the new generation of low frequency radio telescopes reveals the larger population of giant radio galaxies, it offers a significant resource for future analyses.

This book journeys into one of the most fascinating intellectual adventures of recent decades - understanding and exploring the final fate of massive collapsing stars in the universe. The issue is of great interest in fundamental physics and cosmology today, from both the perspective of gravitation theory and of modern astrophysical observations. This is a revolution in the making and may be intimately connected to our search for a unified understanding of the basic forces of nature, namely gravity that governs the cosmological universe, and the microscopic forces that include quantum phenomena. According to the general theory of relativity, a massive star that collapses catastrophically under its own gravity when it runs out of its internal nuclear fuel must give rise to a space-time singularity. Such singularities are regions in the universe where all physical quantities take their extreme values and become arbitrarily large. The singularities may be covered within a black hole, or visible to faraway observers in the universe. Thus, the final fate of a collapsing massive star is either a black hole or a visible naked singularity. We discuss here recent results and developments on the gravitational collapse of massive stars and possible observational implications when naked singularities happen in the universe. Large collapsing massive stars and the resulting space-time singularities may even provide a laboratory in the cosmos where one could test the unification possibilities of basic forces of nature.

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.

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.

Deep within galaxies like the Milky Way, astronomers have found a fascinating legacy of Einstein's general theory of relativity: supermassive black holes. Connected to the evolution of the galaxies that contain these black holes, galactic nuclei are the sites of uniquely energetic events, including quasars, stellar tidal disruptions, and the generation of gravitational waves. This textbook is the first comprehensive introduction to dynamical processes occurring in the vicinity of supermassive black holes in their galactic environment. Filling a critical gap, it is an authoritative resource for astrophysics and physics graduate students, and researchers focusing on galactic nuclei, the astrophysics of massive black holes, galactic dynamics, and gravitational wave detection. It is an ideal text for an advanced graduate-level course on galactic nuclei and as supplementary reading in graduate-level courses on high-energy astrophysics and galactic dynamics.

David Merritt summarizes the theoretical work of the last three decades on the evolution of galactic nuclei, the formation of massive black holes, and the interaction between black holes and stars. He explores in depth such important topics as observations of galactic nuclei, dynamical models, weighing black holes, motion near supermassive black holes, evolution of nuclei due to gravitational encounters, loss cone theory, and binary supermassive black holes. Self-contained and up-to-date, the textbook includes a summary of the current literature and previously unpublished work by the author.

For researchers working on active galactic nuclei, galaxy evolution, and the generation of gravitational waves, this book will be an essential resource.

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.

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.

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.

Astronomers' Universe Series is a new series aimed at active amateur astronomers but is appropriate to a wider audience of astronomically-informed readers. The book provides an up-to-date account of active galaxies. Lists of such objects and their visual and imaged appearance in commercially available telescopes are an important component of this book. The book makes sense of the chaotic and apparently innumerable types of violently active galaxies. It provides the data and teaches the skills needed for users of small telescopes to observe and image some of these "galaxies in turmoil" for themselves.

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).

This book journeys into one of the most fascinating intellectual adventures of recent decades - understanding and exploring the final fate of massive collapsing stars in the universe. The issue is of great interest in fundamental physics and cosmology today, from both the perspective of gravitation theory and of modern astrophysical observations. This is a revolution in the making and may be intimately connected to our search for a unified understanding of the basic forces of nature, namely gravity that governs the cosmological universe, and the microscopic forces that include quantum phenomena. According to the general theory of relativity, a massive star that collapses catastrophically under its own gravity when it runs out of its internal nuclear fuel must give rise to a space-time singularity. Such singularities are regions in the universe where all physical quantities take their extreme values and become arbitrarily large. The singularities may be covered within a black hole, or visible to faraway observers in the universe. Thus, the final fate of a collapsing massive star is either a black hole or a visible naked singularity. We discuss here recent results and developments on the gravitational collapse of massive stars and possible observational implications when naked singularities happen in the universe. Large collapsing massive stars and the resulting space-time singularities may even provide a laboratory in the cosmos where one could test the unification possibilities of basic forces of nature.

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.

Amateur astronomers of all expertise from beginner to experienced will find this a thorough star cluster atlas perfect for easy use at the telescope or through binoculars. It enables practical observers to locate the approximate positions of objects in the sky, organized by constellation. This book was specifically designed as an atlas and written for easy use in field conditions. The maps are in black-and-white so that they can be read by the light of a red LED observer's reading light. The clusters and their names/numbers are printed in bold black, against a "grayed-out" background of stars and constellation figures. To be used as a self-contained reference, the book provides the reader with detailed and up-to-date coverage of objects visible with small-, medium-, and large-aperture telescopes, and is equally useful for simple and computer-controlled telescopes. In practice, GO-TO telescopes can usually locate clusters accurately enough to be seen in a low-magnification eyepiece, but this of course first requires that the observer knows what is visible in the sky at a given time and from a given location, so as to input a locatable object. This is where "The Observer's Guide to Star Clusters" steps in as an essential aid to finding star clusters to observe and an essential piece of equipment for all amateur astronomers.

This volume explains the microscopic physics operating in stars in advanced stages of their evolution and describes with many numerical examples and illustrations how they respond to this microphysics. Models of low and intermediate mass are evolved through the core helium-burning phase, the asymptotic giant branch phase (alternating shell hydrogen and helium burning) and through the final cooling white dwarf phase. A massive model is carried from the core helium-burning phase through core and shell carbon-burning phases. Gravothermal responses to nuclear reaction-induced transformations and energy loss from the surface are described in detail. Written for senior graduate students and researchers who have mastered the principles of stellar evolution, as developed in the first volume of Stellar Evolution Physics, sufficient attention is paid to how numerical solutions are obtained to enable the reader to engage in model construction on a professional level.

Luminous hot stars represent the extreme upper mass end of normal stellar evolution. Before exploding as supernovae, they live out their lives of a few million years with prodigious outputs of radiation and stellar winds, dramatically affecting both their evolution and environments. A detailed introduction to the topic, this book connects the astrophysics of massive stars with the extremes of galaxy evolution represented by starburst phenomena. A thorough discussion of the physical and wind parameters of massive stars is presented. HII galaxies, their connection to starburst galaxies, and the contribution of starburst phenomena to galaxy evolution through superwinds, are explored. The book concludes with the wider cosmological implications, including Population III stars, Lyman break galaxies and gamma-ray bursts, for each of which massive stars are believed to play a crucial role. This book is ideal for graduate students and researchers in astrophysics interested in luminous hot stars and galaxy evolution.

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.

The authors measured atomic hydrogen, the principal component of the interstellar medium in the Milky Way, over a five-year period using the 25-meter radio telescope of the Netherlands Foundation for Research in Astronomy. Displayed in several projections, each map corresponds to a particular velocity interval; separation by velocity roughly corresponds to separation by distance, or by energetics. The Leiden/Dwingeloo survey covers the entire sky above declination -300, on a half-degree grid, over a velocity range of 1000 km/s at 1 km/s resolution. The limiting brightness temperature sensitivity is 0.07 K. A CD-ROM also accompanies the Atlas, and contains the entire dataset of the Leiden/Dwingeloo survey in computer-readable form. The CD-ROM also contains color images in GIF format, as well as animations displaying the 3-dimensional data cube.

This is a comprehensive and richly illustrated textbook on the astrophysics of the interstellar and intergalactic medium--the gas and dust, as well as the electromagnetic radiation, cosmic rays, and magnetic and gravitational fields, present between the stars in a galaxy and also between galaxies themselves. Topics include radiative processes across the electromagnetic spectrum; radiative transfer; ionization; heating and cooling; astrochemistry; interstellar dust; fluid dynamics, including ionization fronts and shock waves; cosmic rays; distribution and evolution of the interstellar medium; and star formation. While it is assumed that the reader has a background in undergraduate-level physics, including some prior exposure to atomic and molecular physics, statistical mechanics, and electromagnetism, the first six chapters of the book include a review of the basic physics that is used in later chapters. This graduate-level textbook includes references for further reading, and serves as an invaluable resource for working astrophysicists. * Essential textbook on the physics of the interstellar and intergalactic medium * Based on a course taught by the author for more than twenty years at Princeton University * Covers radiative processes, fluid dynamics, cosmic rays, astrochemistry, interstellar dust, and more * Discusses the physical state and distribution of the ionized, atomic, and molecular phases of the interstellar medium * Reviews diagnostics using emission and absorption lines * Features color illustrations and detailed reference materials in appendices * Instructor's manual with problems and solutions (available only to teachers)

The past two decades have seen remarkable advances in observations of sunspots and their magnetic fields, in imaging of spots and fields in distant stars and in associated theoretical models and numerical simulations. This book provides a comprehensive combined account of the properties of sunspots and starspots. It covers both observations and theory, and describes the intricate fine structure of a sunspot's magnetic field and the prevalence of polar spots on stars. The book includes a substantial historical introduction and treats solar and stellar magnetic activity, dynamo models of magnetic cycles, and the influence of solar variability on the Earth's magnetosphere and climate. This volume is a valuable reference for graduate students and specialists in solar and stellar physics, astronomers, geophysicists, space physicists and experts in fluid dynamics and plasma physics.