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.

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.

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.

An epic adventure featuring danger, dragons and a fight against destiny. "A smart, original, fantasy adventure" Dominique Valente, author of Starfell "Richly imagined and unputdownable" Vashti Hardy, author of Brightstorm When Paisley Fitzwilliam is summoned to receive the track of stars that will determine her future, she is filled with hope for the future. But the fate she is dealt throws everything upside down. Then her mother goes missing and the closely guarded secret around her brother Dax is more at risk than ever before. It seems that the previous metal nightsilver might hold the key. . . Can Paisley defy her stars and change the course of history? A breathtaking journey through the Floating Boroughs and the dark sewers of London, capital city of the Empire of Albion. A thrilling fantasy debut with immersive world-building and tons of action! Perfect for readers of Philip Pullman, Diana Wynne Jones and Cornelia Funke. The first book in a bold new trilogy, destined to be a future classic.

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.

Planetary Nebulae and How to Observe Them is for amateur astronomers who want to go beyond the Messier objects, concentrating on one of the most beautiful classes of astronomical objects in the sky. Planetary nebulae are not visible to the naked eye, but they are a fascinating group of telescope objects. This guide enables a user equipped with an average-sized amateur telescope to get the best out of observing them. Topics covered include their astrophysical make-up, history of their discovery, classification and description, telescopes to use, filters, and observing techniques - in short everything anyone would need to know to successfully observe planetary nebulae. The book describes the various forms these astronomical objects can take and explains why they are favorite targets for amateur observers. Descriptions of over 100 nebulae personally observed by the author using telescopes of various sizes are included in the book. Readers can create their own observing program or follow the list of these captivating objects, many of which are found within our own Milky Way Galaxy.

From prehistoric times, mankind has looked up at the night sky, and puzzled at the changing positions of the stars. How far away they are is a question that has confounded scientists for centuries. Over the last few hundred years, many scientific careers and considerable resources have been devoted to measuring their positions and motions with ever increasing accuracy. And in the last two decades of the 20th century, the European Space Agency developed and launched the Hipparcos satellite, around which this account revolves, to carry out these exacting measurements from space.

What has prompted these remarkable developments? Why have governments been persuaded to fund them? What are scientists learning from astronomy's equivalent of the Human Genome Project? This book traces the subject's history, explains why such enormous efforts are considered worthwhile, and interweaves these with a first-hand insight into the Hipparcos project, and how big science is conducted at an international level. The involvement of amateur astronomers, and the Hipparcos contributions to climate research, death stars' passing close to the Sun, and the search for extra-solar planets and even intelligent life itself, are some of the surprising facets of this unusual space mission.

This is the first comprehensive treatment of active galactic nuclei--the cosmic powerhouses at the core of many distant galaxies. The term "active galactic nuclei" refers to quasars, radio galaxies, Seyfert galaxies, blazars, and related objects, all of which are believed to share a similar central engine--a supermassive black hole many times the mass of the Sun. Astrophysicists have studied these phenomena for the past several decades and have begun to develop a consensus about many of their properties and internal mechanisms. Julian Krolik, one of the world's leading authorities on the subject, sums up leading ideas from across the entire range of research, making this book an invaluable resource for astronomers, physicists interested in applications of the theory of gravitation, and graduate students.

Krolik begins by addressing basic questions about active galactic nuclei: What are they? How can they be found? How do they evolve? He assesses the evidence for massive black holes and considers how they generate power by accretion. He discusses X-ray and g-ray emission, radio emission and jets, emission and absorption lines, anisotropic appearance, and the relationship between an active nucleus and its host galaxy. He explores the mysteries of what ignites, fuels, and extinguishes active galactic nuclei, and concludes with a general review of where the field now stands. The book is unique in paying careful attention to relevant physics as well as astronomy, reflecting in part the importance of general relativity to understanding active galactic nuclei. Clear, authoritative, and detailed, this is crucial reading for anyone interested in one of the most dynamic areas of astrophysics today.

The spectacular images of galaxy collisions capture the imagination. This book will show what is out there in the universe, what it's like in other galaxies, what they might look like, and how cosmic processes might affect life in other solar systems. It will explain crucial stages in the development of physical structure in the universe, and the effect of galaxy scale processes. Professor Struck will explore all the issues surrounding galaxy collisions. He will begin with a brief broad review of the background on galaxies, the history of their discovery, and how this has been driven by steadily improving technology. Chapters 2 gives details of the early stages of different types of galaxy collision - Rings of Fire, Tidal Swings and Retrograde and Sideways Reels - while Chapter 3 describes collisions between galaxies of very different masses: minor merger or dwarf destruction. Chapter 4 covers ultra-luminous infrared galaxies and major mergers and Chapter 5 briefly examines the techniques used for computer simulation results and how increasing computer capacity has affected the development of this field. The following chapter looks at understanding the physical processes of triggered star formation and nuclear activity. Chapters 7-9 look at the broader view of cosmological structure growth which determines the environment and conditions in which galaxy collisions occur. In the densest environments, this process repeats itself on the larger scale of galaxy clusters. The concluding chapter considers what a galaxy collision looks like from a solar system like ours. Although the galaxy is completely restructured and the night sky view would change greatly over the course of several hundred million years, the direct effects on our planet would be few and infrequent, with only a small probability of being truly catastrophic. These issues will be explored along with the ideas that galaxies must reach a certain evolutionary "maturity" before they can even form solar systems, and that there are habitable zones within galaxies. Thus, galaxy scale processes, like collisions, can determine the fate of life on Earth-like planets.

I have spent many wonderful nights observing at a variety of places around the world, but many of my fondest memories come from those made at the Custer Observatory in Southold on Long Island, where I grew up. I was only perhaps a dozen years old when I started out, and now more than three decades later I have logged millions of miles on the various telescopes there. Some of the best memories are of observing and discussing astronomical topics with the many really terrific people who make up Custer. It truly holds a special place in my heart. Star clusters were always among my favorite objects to observe and discuss there. This book is the result of the exposure to these objects, many of which I observed for the first time at Custer. The Custer Institute Observatory was founded in the 1920s by local resident Charles W. Elmer of Perkin-Elmer Corp. fame. The original crew met at his house in Cedar Beach a few miles down the road from the institute. In the 1930s the group built an observatory complete with Mr. Elmer's donated 5" Alvan Clark refractor. Later the observatory expanded to include a 6" Clark refractor and other even larger instruments.

The Moon is not just a static piece of cosmic matter in our night sky, but a dynamic living being. Throughout her journey around the Earth which takes about 29.5 days she shows us her different faces, growing from a silver sliver in the sky to an awe-inspiring illuminated sphere, before returning to darkness again. She changes colour and moves through a variety of star constellations reflecting the energies at play each day. The Moon gives us a map to a cyclical way of living; the blueprint for a life that breathes in harmony with the rhythm of the natural world around us. She teaches us about the importance of embracing quiet and reflective times as much as celebrating the times we experience life in its fullest expression. She informs us when to plant the seeds of our dreams and when to take stock and harvest what we have been growing. What will you discover about yourself when you tune into the moon?

A Spectroscopic Atlas of the Stars: A Pocket Field Guide is a standard reference book for all amateur astronomers interested in practical spectroscopy or spectrography. For the first time in one place, it identifies more than 70 (northern hemisphere) bright stars that are suitable observational targets for both amateurs and astronomy students.

Finder charts are provided for locating these sometimes-familiar stars. Data for each star includes labelled stellar spectra, a spectral profile with spectral lines identified. These are conveniently laid out on a single page, opposite tables of spectroscopic properties, and lines and wavelengths identified.

This is the first Spectral Atlas designed for amateur astronomers. It is equally relevant to college undergraduates, being intended to familiarize astronomers of any age and level of knowledge with labelled stellar spectra and their different properties. It contains much information about stars which is hard to find or inaccessible to most people.

Amateur astronomers are always on the lookout for new observing challenges. This exciting book retraces the steps of the greatest visual observer and celestial explorer who ever lived. This is a practical guide to locating and viewing the most impressive of Herschel 's star clusters, nebulae and galaxies, cataloging more than 600 of the brightest objects, and offering detailed descriptions and images of 150 to 200 of the best.

ASTRONOMERSa (TM) OBSERVING GUIDES provide up-to-date information for amateur astronomers who want to know all about what it is they are observing. This is the basis of the first part of the book. The second part details observing techniques for practical astronomers, working with a range of different instruments.

Star Clusters and How to Observe Them is a mine of information for all levels of amateur observers, from beginners to experienced observers. It begins with a detailed yet easily assimilated description of star clusters, how they were formed as our Milky Way galaxy evolved, and how they are classified. The latest research has revealed a vast amount of fascinating information about the clusters, along with some spectacular photographs.

Modern commercially-made telescopes enable amateur astronomers to see a surprising amount of detail, and to record a" using CCD cameras, video, webcams or even film a" some remarkably beautiful and detailed images. There is detailed information on using refractors, reflectors, SCTa (TM)s (like Meade and Celestron) and computer-controlled telescopes

The book includes an Observing List cataloguing star clusters to be observed or imaged using a variety of different instruments, all of them available commercially to amateur astronomers.

Written specially for practical amateur astronomers who not only want to observe, but want to know and understand the details of exactly what they are looking at.

Presents an up-to-date detailed description of the objects, their physics and their evolution (part one); and then (part two) to consider how to observe and record them successfully.

Delivers a wealth of information for all levels of amateur observers, from the beginner to the experienced; it is equally fascinating for practical astronomers, and also for those who simply want to find out more about these unusual star systems.

This text presents numerous illustrations of the observed variability of cataclysmic variable stars. It provides a clear explanation and thorough up-to-date overview of this phenomena at a level accessible to the advanced amateur or undergraduate student.

Galactic dynamics is fundamental to understanding the formation of galaxies, their internal evolution and their current structure. While galactic dynamics has traditionally focused on the evolution of the stellar components of galaxies, studies over the past two decades have shown that all aspects of galaxy evolution are strongly influenced by the interplay between the dynamics of stars, gas, and dark matter. IAU Symposium 353, is the first major symposium in more than a decade focused on the dynamics of galaxies and stellar systems, covering the recent explosion in the availability of kinematical data both for individual stars in the Milky Way and wide field line-of-sight kinematics for large samples of external galaxies. These proceedings describe recent developments that aim to transform our understanding of the dynamics, structure, formation and evolution of our own host galaxy, the Milky Way, as well as galaxies in the universe at large.

Part of the reissued Oxford Classic Texts in the Physical Sciences series, this book was first published in 1983, and has swiftly become one of the great modern classics of relativity theory. It represents a personal testament to the work of the author, who spent several years writing and working-out the entire subject matter.

The theory of black holes is the most simple and beautiful consequence of Einstein's relativity theory. At the time of writing there was no physical evidence for the existence of these objects, therefore all that Professor Chandrasekhar used for their construction were modern mathematical concepts of space and time. Since that time a growing body of evidence has pointed to the truth of Professor Chandrasekhar's findings, and the wisdom contained in this book has become fully evident.

IAU symposium 165 'Compact Stars in Binaries' was held from 15 through 19 August 1994, as part of the 22nd General Assembly of the IAU in The Hague. The symposium, supported by IAU Commissions 35,37,44 and 48, and co-sponsored by Commission 42, was attended by about 400 to 500 participants. This symposium received support from: - The International Astronomical Union; - The Royal Netherlands Academy of Sciences; - The Netherlands Ministery of Education and Science; - The Leids Kerkhoven Bosscha Fonds; - The Stichting Fysica. The field of compact stars in binaries is one of the most active areas of present-day astrophysics. An absolute highlight of the last few years was the 1993 Nobel Prize of physics, awarded to Taylor and Hulse for their discovery of the binary pulsar PSR 1913+ 16, and the measurement of the orbital decay of this system due to the emission of gravitational waves. The aim of the organizers of the symposium was to present an overview of the most significant observational discoveries of the past decade, in com bination with a review of the most important theoretical developments. We were very happy that most of the world's leading experts in observation and theory were present at the symposium to review the various aspects of the subject. The contents of their oral presentations are now published in the form of these proceedings, which we expect to become an important source of reference for the coming years.

IAU Symposium 103 was held at University College London, August 9-13 1982. This volume contains the proceedings of the meetin- invited papers, abstracts of contributed papers, and discussion. As is nON custanary with the proceedings of IAU Symposia, the manuscript was canpiled fran camera-ready copy. The Editor was responsible for the preparation of the abstracts of the contributed papers and the discussion, the authors of the invited papers for the preparation of their 0Nn reviews. The discussion at the meeting was lively and infonnative, and the Editor hopes that a reasonably faithful and readable record of the discussion is to be found in these proceedings. In accordance with the wish of the Scientific Organising Committee, an object index has been canpiled and appended. It is to be hoped that the index will augment the usefulness of the volune. The Editor is greatly indebted to M. J. Barlow for his help in preparing the index. Financial assistance for the meeting was provided by the IAU and University College London. The hospitality received during the excursion to the Old Royal Observatory and National Maritime MUseum, Greenwich, is gratefully acknowledged. The task of editing these proceedings has been greatly facilitated by the excellent secretarial assistance of V. A. Kerr. David Flower Durham, October 1982 xiii D. R. Flower (ed.), Planetary Nebulae, xiii.

The world of science has been transformed. 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.

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.

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.