This book contains the proceedings of the first large IAU Symposium dedicated to the bulges of spiral galaxies. Detailed attention is paid to the bulge of the Milky Way, one of the major building blocks of this system. Topics include the definition of the bulge in our Galaxy and its relation to the so-called spheroid. Discussions are presented regarding the stars contained in this bulge, their astrophysical properties, their motions and the metallicity variations which appear to be present. The possible existence of a bar in the bulge and its origin and future are also examined. The same topics are discussed in less detail for the bulges of other galaxies.

Interstellar dust grains catalyse chemical reactions, absorb, scatter, polarise and re-radiate starlight and constitute the building blocks for the formation of planets. Understanding this interstellar component is therefore of primary importance in many areas of astronomy & astrophysics. For example, observers need to understand how dust effects light passing through molecular clouds. Astrophysicists wish to comprehend how dust enables the collapse of clouds or how it determines the spectral behaviour of protostars, star forming regions or whole galaxies. This book gives a thorough theoretical description of the fundamental physics of interstellar dust: its composition, morphology, size distribution, dynamics, optical and thermal properties, alignment, polarisation, scattering, radiation and spectral features.
This encyclopedic book provides the basic physics towards understanding the solid matter in interstellar space. It includes all the necessary physics, including solid state physics, radiative transport, optical properties, thermodynamics, statistical mechanics and quantum mechanics. It then uses all of this basic physics in the specific case of dust grains in the interstellar medium.
Interstellar dust clouds catalyze simple chemical reactions, absorbs, scatters, polarizes and re-radiates starlight and forms the building blocks for planet and stellar formation. Understanding this interstellar medium is then of primary importance in many areas of astronomy & astrophysics. For example observers need to understand how it effects light passing through dust and molecular clouds, astrophysicists need to comprehend the formation and structure of dust clouds and how it collapses to form stars and planets.
Written in an accessible and descriptive manner, this will be essential supplementary reading for advanced undergraduate and graduate students taking courses on the interstellar medium and active researchers in need of a single source of well illustrated and detailed information.

Olbers' paradox states that given the Universe is unbounded, governed by the standard laws of physics, and populated by light sources, the night sky should be ablaze with light. Obviously this is not so. However, the paradox does not lie in nature but in our understanding of physics. A Universe with a finite age, such as follows from big-bang theory, necessarily has galaxies of finite age. This means we can only see some of the galaxies in the Universe, which is the main reason why the night sky is dark. Just how dark can be calculated using the astrophysics of galaxies and stars and the dynamics of relativistic cosmology.
We know from the dynamics of individual galaxies and clusters of galaxies that the majority of matter that exerts gravitational forces is not detectable by conventional telescopes. This dark matter could have many forms, and candidates include various types of elementary particles as well as vacuum fluctuations, black holes, and others. Most of these candidates are unstable to decay and produce photons. So dark matter does not only affect the dynamics of the Universe, but the intensity of intergalactic radiation as well. Conversely, we can use observations of background radiation to constrain the nature and density of dark matter.
By comparing observational data with cosmological theory based on general relativity and particle physics, Dark Sky, Dark Matter reviews our present understanding of the universe and the astrophysics of the night sky and dark matter.

Initially this book focuses on the chemical and morphological properties of dust particles, both cosmological and terrestrial, and some of techniques used to gain information. When light or other electromagnetic radiation interacts with dust or other particles it is scattered in all directions. The scattering interaction are relevant to many fields of science: dust affects communications, dust particles affect the output of aerosol monitors, and dust particles are an important astrophysical component, making up a large part of the dark matter in the universe. The electromagnetic forces exerted on these particles may play an important role in bringing the particles together to form larger astronomical bodies.Optics of Cosmic Dust describes what we currently know about cosmic dust, how we know it, and the research efforts undertaken to provide that knowledge. Areas treated include observational information, dust morphology and chemistry, light-scattering models, characterisation methodologies, and backscatter polarisation and dynamics. Suitable as an introductory text, the book is also a reference guide for the advanced researcher.

The objective of this meeting was to bring together collea gues from different branches of observational astronomy and theoretical astrophysics to discuss and analyse the rapid progress in our knowledge and understanding of the matter surrounding stars, streaming off stellar surfaces, or fall ing onto stars. The meeting was sponsored by IAU Commis sions 36 (Theory of Stellar Atmospheres), 29 (Stellar Spec tra), and 34 (Interstellar Matter). There were two special reasons for organizing this meeting at Heidelberg in 1986: During this year the University of Heidelberg celebrated its 600th anniversary and the IAU symposium joined the many scientific events accompanying this celebration. Secondly, the year 1986 also marked the conclusion of a special co operative research project ("Sonderforschungsbereich") in astrophysics at Heidelberg, a major part of which had been devoted to the physics of circumstellar matter. The main topics discussed at this meeting were: (1) circumstellar matter, bipolar flows, and jets from young stars and protostars; (2) circumstellar envelopes of evolved stars; (3) stellar coronae; (4) stellar winds from hot and cool stars; (5) dust formation and circumstellar chemistry. Many exciting new results were presented in 21 invited or review papers, 26 contributed papers, and 127 poster papers. This symposium would not have been possible without the generous financial assistance of the International Astronomical Union, the German Science Foundation (DFG), and the State Government of Baden-Wurttemberg. The practi cal support of the University of Heidelberq and the Max Planck-Society was also very valuable."

'A book that will make the night sky your lifelong passion. An invitation to immerse yourself in the nature around you and the universe beyond.' - Professor Brian Cox The Secret World of Stargazing is the ultimate astronomy book to set you on your epic journey around the cosmos - it's a simple guide to the skies and makes stargazing fun, easy and enjoyable for all - absolutely no equipment is required! Adrian West, AKA the internet sensation VirtualAstro, will take you through the seasons, showing you exactly what you can spot in the sky throughout the year, whether you're in your back garden or sitting on an exotic beach somewhere! While you're learning how to spot constellations, meteors and comets, you will be switching off your busy mind, sitting still in nature and paying attention to the small details that make up the big picture of life. You'll finish reading this beautiful book and come away with a sense of grounding, connection, knowledge and a whole new appreciation of the sky above and the world outside your own - it will soothe your soul. 'An excellent, readable, bright guide to the night sky.' - Dara O'Briain 'A superb introduction to astronomy.' - Chris Packham

The high time-resolution radio sky represents unexplored astronomical territory. This thesis presents a study of the transient radio sky, focussing on millisecond scales. As such, the work is concerned primarily with neutron stars. In particular this research concentrates on a recently identified group of neutron stars, known as RRATs, which exhibit radio bursts every few minutes to every few hours. After analysing neutron star birthrates, a re-analysis of the Parkes Multibeam Pulsar Survey is described which has resulted in the discovery of 19 new transient radio sources. Of these, 12 have been seen to repeat and a follow-up campaign of observations has been undertaken. These studies have greatly increased our knowledge of the rotational properties of RRATs and enable us to conclude that they are pulsars with extreme nulling and/or pulse-to-pulse modulation. Although the evolution of neutron stars post-supernova is not yet understood, it seems that RRATs fit into the emerging picture in which pulsar magnetospheres switch between stable configurations.

Galaxies have a history: distant galaxies, formed early in the life of the universe, differ from the nearby ones. This book addresses the modeling of galaxy evolution from their cosmological formation to their presently observable structures, presenting the state of the art in the field.

This volume presents the results of the workshop discussions on the jet phenomenon on different astrophysical scales and covers interdisciplinary areas such as steady state winds, time-dependent winds/jets, jet energetics and jet/wind propagation.

The Cosmos Explained is an exciting and beautifully designed book that charts the life of our universe from the Big Bang to the present day and beyond. Starting with the moment of the Big Bang-at exactly one ten-millionth of a trillionth of a trillionth of a trillionth of a second-this book charts a history of space and time all the way through the evolution of our solar system, the birth of stars and the formation of life on Earth, to the future of our galaxy and beyond. With deeply insightful and fascinating text by Hayden Planetarium Associate Professor Charles Liu, who also hosts the immensely popular StarTalk podcast, this book is an accessible and enthralling gateway into the mysteries of space, time and the universe. Pinpoint exactly where you are in space and time using the timeline at the bottom of every page, and explore the history of the cosmos and the science behind it through beautiful telescope images and striking illustrations. Packaged in a unique retro design that reflects the 1960s cosmonaut era but still feels modern and relevant today, this title is as rich with information as it is with stunning visualisations of the concepts and bodies detailed within. An ideal gift for anyone interested in space or curious about the cosmos, The Cosmos Explained is a unique and entertaining timeline of life, the universe, and everything!

Dust is widespread in the galaxy. To astronomers studying stars it may be just an irritating fog, but it is becoming widely recognized that cosmic dust plays an active role in astrochemistry. Without dust, the galaxy would have evolved differently, and planetary systems like ours would not have occurred.
To explore and consolidate this active area of research, Dust and Chemistry in Astronomy covers the role of dust in the formation of molecules in the interstellar medium, with the exception of dust in the solar system. Each chapter provides thorough coverage of our understanding of interstellar dust, particularly its interaction with interstellar gas. Aimed at postgraduate researchers, the book also serves as a thorough review of this significant area of astrophysics for practicing astronomers and graduate students.

This book addresses the fascinating subject of astrophysics from its theoretical basis to predominant research conducted in the field today. An accomplished researcher in the field and a well-known expositor, the author strikes a balance that allows the serious reader to appreciate the current issues without previous knowledge of the subject.Astronomy and Astrophysics * The Equations of Stellar Structure * The Gas Characteristics * The Structure of a Star * Computation of Stellar Evolution * Evolutionary Track * Binary Systems * Star Formation * Rotation of Stars * Supernova * Close Binary Systems * Special Topics * The Galaxy

The point of this book is to provide a brief, easy-to-read but comprehensive overview of stars: where they came from; what they are made of; what will happen to them, and what they mean to us from a scientific, aesthetic and cultural point of view. The book will focus on stars and astronomy, and will keep technical physics to a minimum.

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

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.

Star-formation is one of the key processes that shape the current state and evolution of galaxies. This volume provides a comprehensive presentation of the different methods used to measure the intensity of recent or on-going star-forming activity in galaxies, discussing their advantages and complications in detail. It includes a thorough overview of the theoretical underpinnings of star-formation rate indicators, including topics such as stellar evolution and stellar spectra, the stellar initial mass function, and the physical conditions in the interstellar medium. The authors bring together in one place detailed and comparative discussions of traditional and new star-formation rate indicators, star-formation rate measurements in different spatial scales, and comparisons of star-formation rate indicators probing different stellar populations, along with the corresponding theoretical background. This is a useful reference for students and researchers working in the field of extragalactic astrophysics and studying star-formation in local and higher-redshift galaxies.

I. Initial Angular Momentum Distribution.- Angular Momentum Effects in Star Formation.- Evolutionary Properties of Intermediate-Mass Protostar.- Small-Scale Structure and Angular Momentum Transfer in Protostellar Environments.- Ekman Pumping in a Rotating Protostar.- Rotation in Pre-Main Sequence Stars; Properties and Evolution.- Disks Associated with Intermediate Mass Stars.- Differential Rotation of Fully Convective Pre-Main Sequence Stars.- The X-ray Emission from PMS Stars in Taurus-Auriga, and the Relationship with Other Diagnostics of Activity.- Multifrequency Monitoring of RU Lupi; Observational Results and a Model.- Polarimetry and CCD Imaging of Herbig Ae/Be Stars and Star Forming Regions.- II: Angular Momentum Evolution.- Rotational Velocities of Low Mass Stars in Young Clusters.- Rotation of Young Stars in the Orion Nebula Region.- Rotational Velocities of Stars in Open Clusters; the Time-Dependence Revisited.- Main Sequence Angular Momentum Loss in Low-Mass Stars.- The Angular Momentum Evolution of Young and Old Binary Components.- Ages of Spotted Late-Type Stars.- Rotation of Evolved Stars.- Rotational Discontinuity of Evolved Stars; What Interpretation?.- III: Consequence of Rotation.- Magnetic Activity and Rotation.- Lithium, Rotation and Age.- Rotation, Chromospheric Activity, and Lithium Abundances in G and K Dwarfs of the Pleiades.- Lithium Abundance and Rotation in Southern Chromospherically Active Stars.- Lithium Depletion Induced by Rotation in Young Stars.- Rotational Mixing and Lithium in Young Stars.- IV: Internal Rotation and Models.- Internal Solar Rotation.- Stellar Activity Belts as Potential Indicators of Internal Rotation and Angular Momentum Distribution.- Dynamics of Spot Groups and Rotation of the External Convective Layers in the Sun and Magnetically Active Stars.- Theory of Magnetic Braking of Late-Type Stars.- Pre-Main Sequence and Main Sequence Rotational Evolution; Constraints on Models Derived from Observations.- Evolutionary Models of Rotating Stars.- The Internal Rotation of the Sun; Implications on the History of its Angular Momentum.- Angular Momentum Transport, Rotational Instabilities, Magnetic Fields and Mixing.- The Spin-Down of Main Sequence Stars Based on Observed Magnetic Field Strength.- Session V: Observational Perspectives.- Observational Perspectives.- PRISMA: a Space Facility for Studying Rotation and Activity.- The Spectrum-UV Project.- Summary of the Workshop.- Panel Discussion: Initial Angular Momentum.- Panel Discussion: Dynamos and Internal Rotation.- Author Index.- Object Index.

From time immemorial, poets and philosophers have looked in awe and wonder at the Universe. Such awe is shared by astrophysicists, too, as they seek to understand its nature, and whether it has any limits. In The Infinite Cosmos, Joseph Silk, Savilian Professor of Astronomy at Oxford University, cosmologist and well-known science writer, brings together the modern understanding of the Universe, its structure, its evolution, and its possible fate, combining the latest from theory and observation. The narrative is peppered with quotations from literature and philosophy, and reflects, too, on the process of scientific discovery, and the implications of our discoveries.

Your Passport to the Universe

The night sky is alive with many wonders––distant planets, vast star clusters, glowing nebulae, and expansive galaxies, all waiting to be explored. Let respected astronomy writer Philip Harrington introduce you to the universe in Star Watch, a complete beginner’s guide to locating, observing, and understanding these celestial objects. You’ll start by identifying the surface features of the Moon, the banded cloud tops of Jupiter, the stunning rings of Saturn, and other members of our solar system. Then you’ll venture out beyond our solar system, where you’ll learn tips and tricks for finding outstanding deep-sky objects from stars to galaxies, including the entire Messier catalog––a primary goal of every serious beginner.

Star Watch features a detailed physical description of each target, including size, distance, and structure, as well as concise directions for locating the objects, handy finder charts, hints on the best times to view each object, and descriptions of what you’ll really see through a small telescope or binoculars and with the naked eye.

Star Watch will transport you to the farthest depths of space––and return you as a well-traveled, experienced stargazer.

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.

Whether stargazing with the naked eye or observing deep space with the largest telescopes in the world, humans have a seemingly neverending fascination with the stars. Our ancestors saw patterns in their random arrangement, inventing both tales of legendary heroes and the pastime of dot-to-dot in one fell swoop. But it's only in the last century or so that the natures of these distant lights have been revealed - and it's more incredible than any legend. How are stars born? How long do they live? And just how many times can you read the word 'trillion' before it starts sounding made up? Find out as astronomer Dr Greg Brown of Royal Observatory Greenwich takes a short diversion from obsessing over black holes to illuminate us about the lives of stars - ending in black holes, naturally.

This comprehensive overview of stellar astrophysical fluid dynamics includes properties of pulsating stars; helioseismology; convection and mixing in stellar interiors; and dynamics of stellar rotation, planet formation and the generation of stellar and planetary magnetic fields. Each chapter is written by a leading expert in the field and extensive references to technical literature are made.

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.

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.