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.

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.

SHORTLISTED FOR THE ROYAL SOCIETY SCIENCE BOOK PRIZE 2021 FINALIST FOR THE PEN/E.O. WILSON LITERARY SCIENCE WRITING AWARD AN AMAZON BEST BOOK OF 2020 To be an astronomer is to journey to some of the most inaccessible parts of the globe, braving mountain passes, sub-zero temperatures, and hostile flora and fauna. Not to mention the stress of handling equipment worth millions. It is a life of unique delights and absurdities ... and one that may be drawing to a close. Since Galileo first pointed his telescope at the heavens, astronomy has stood as a fount of human creativity and discovery, but soon it will be the robots gazing at the sky while we are left to sift through the data. In The Last Stargazers, Emily Levesque reveals the hidden world of the professional astronomer. She celebrates an era of ingenuity and curiosity, and asks us to think twice before we cast aside our sense of wonder at the universe.

This book provides a valuable learning tool to facilitate identifying patterns and stars in the sky. Suitable for observers using binoculars and medium size telescopes, this catalog includes star pictures, dot-to-dot outlines of the objects (on a negative photograph for clarity), and an artistic image next to the star patterns. Size, stellar magnitudes, and coordinates are provided, along with north direction, star-hopping instructions and Sky Atlas 2000 references. With the help of this book, the imaginative observer will soon begin to develop a new insight into star patterns, and will start seeing patterns of their own.

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.

This research monograph presents a new dynamical framework for the study of secular morphological evolution of galaxies along the Hubble sequence. Classical approaches based on Boltzmann's kinetic equation, as well as on its moment-equation descendants the Euler and Navier-Stokes fluid equations, are inadequate for treating the maintenance and long-term evolution of systems containing self-organized structures such as galactic density-wave modes. A global and synthetic approach, incorporating correlated fluctuations of the constituent particles during a nonequilibrium phase transition, is adopted to supplement the continuum treatment. The cutting-edge research combining analytical, N-body simulational, and observational aspects, as well as the fundamental-physics connections it provides, make this work a valuable reference for researchers and graduate students in astronomy, astrophysics, cosmology, many-body physics, complexity theory, and other related fields. Contents Dynamical Drivers of Galaxy Evolution N-Body Simulations of Galaxy Evolution Astrophysical Implications of the Dynamical Theory Putting It All Together Concluding Remarks Appendix: Relation to Kinetics and Fluid Mechanics

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.

Binary systems of stars are as common as single stars. Stars evolve primarily by nuclear reactions in their interiors, but a star with a binary companion can also have its evolution influenced by the companion. Multiple star systems can exist stably for millions of years, but can ultimately become unstable as one star grows in radius until it engulfs another. This volume, first published in 2006, discusses the statistics of binary stars; the evolution of single stars; and several of the most important kinds of interaction between two (and even three or more) stars. Some of the interactions discussed are Roche-lobe overflow, tidal friction, gravitational radiation, magnetic activity driven by rapid rotation, stellar winds, magnetic braking and the influence of a distant third body on a close binary orbit. A series of mathematical appendices gives a concise but full account of the mathematics of these processes.

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.

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 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).

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.

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.

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.

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.

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.

ThisvolumeisacollectionofarticlesoriginallypublishedonaSpecialIssueoftheAstrophysicsandSpaceScienceJournal. It is intended to give a comprehensive overview of the current state of knowledge in solar and stellar modelling, with the aim of comparing and extending what we know from the detailed solar modelling, made possible by the helioseismic tools and by the recent analysis of the solar spectrum, to the modelling and understanding of generic stellar structures and their evolution. Particular emphasis is devoted to the role of the input physics, and its relevant uncertainties, in the construction of stellar models and in the resulting predictions for general observable quantities. Issues related to convection, overshoot, diffusion and settling of helium and heavy elements, rotation, chemical composition and magnetic eld are extensively discussed. Large space is dedicated to the application of helio- and asteroseismic techniques as tools to prove the theory of the evolution and the structure of the stars. Comments on prospects for future improvements and re nements of the theoretical models are given, focusing on the possibility of getting ever more precise helioseismic and asteroseismic observations from ground and space. The articles included in this volume are the results of the HELAS-NA5 workshop 'Synergies between solar and stellar modelling' held in Rome from 22nd to 26th of June 2009, which was an unique occasion to gather the solar and the stellar physics communities to discuss the urgent questions risen by recent photometric and spectroscopic observational results.