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.

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.

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.

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.

'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

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

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.

Carbon plays a fundamental role on Earth. It forms the chemical backbone for all essential organic molecules produced by living organisms. Carbon-based fuels supply most of society's energy, and atmospheric carbon dioxide has a huge impact on Earth's climate. This book provides a complete history of the emergence and development of the new interdisciplinary field of deep carbon science. It traces four centuries of history during which the inner workings of the dynamic Earth were discovered, and documents extraordinary scientific revolutions that changed our understanding of carbon on Earth forever: carbon's origin in exploding stars; the discovery of the internal heat source driving the Earth's carbon cycle; and the tectonic revolution. Written with an engaging narrative style and covering the scientific endeavours of more than a hundred pioneers of deep geoscience, this is a fascinating book for students and researchers working in Earth system science and deep carbon research.

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.

The formation of the first supermassive black holes is one of the main open questions in our understanding of high-redshift structure formation. In this book, we aim to provide a summary of state-of-the-art modern research on this topic, exploring the formation of massive black holes from a fluid-dynamical, stellar-dynamical and chemical perspective. The book thus presents a solid theoretical foundation, a comparison with current observations and future observational perspectives with upcoming missions such as the Square Kilometre Array, the European Extremely Large Telescope, the Euclid satellite as well as possible detections via gravitational waves.

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.

"If you buy just one guide...you won't do better than this" BBC Sky at Night Magazine "I will continue to enjoy 'Philip's Stargazing' as the months go by" Helen Sharman, Astronaut "Very useful indeed" Chris Lintott, Sky at Night presenter Now including the top astronomical places to visit, star festivals and the latest on star parties in Britain and Ireland, the new 2023 edition is totally up-to-date for exploring the wonder of the night skies, month-by-month and day-by-day. Whether you're a seasoned astronomer or just starting out, Philip's Stargazing 2023 is the only book you'll need. Compiled by experts and specially designed for easy and daily use, Stargazing 2023 acts as a handily illustrated and comprehensive companion. - 12 updated sky charts for year-round astronomical discovery - Month-to-Month information. Daily Moon Phase Calendar, highlighting special lunar events throughout the year - Planet Watch for ideal viewing days in 2023 - The best places to experience Dark Skies, along with the latest on Star Festivals and Star Parties - Top places to visit for astronomical insights - Expert advice and insight throughout from internationally renowned Prof Nigel Henbest - The latest on electronic telescopes from expert Robin Scagell - Complete calendar of major astronomical events, including the Top 20 Sky Sights of 2023 - Jargon Buster, explaining common or confusing terms - The planets' movements explained from solar and lunar eclipses to meteor showers and comets

By the star physicist and author of multiple #1 Sunday Times bestsellers, a major and definitive narrative work on black holes and how they can help us understand the universe.

At the heart of our galaxy lies a monster so deadly it can bend space, throwing vast jets of radiation millions of light years out into the cosmos. Its kind were the very first inhabitants of the universe, the black holes.

Today, across the universe, at the heart of every galaxy, and dotted throughout, mature black holes are creating chaos. And in a quiet part of the universe, the Swift satellite has picked up evidence of a gruesome death caused by one of these dark powers. High energy X-ray flares shooting out from deep within the Draco constellation are thought to be the dying cries of a white dwarf star being ripped apart by the intense tides of a supermassive black hole – heating it to millions of degrees as it is shredded at the event horizon.

They have the power to wipe out any of the universe’s other inhabitants, but no one has ever seen a black hole itself die. But 1.8 billion light years away, the LIGO instruments have recently detected something that could be the closest a black hole gets to death. Gravitational waves given off as two enormous black holes merge together. And now scientists think that these gravitational waves could be evidence of two black holes connecting to form a wormhole – a link through space and time. It seems outlandish, but today’s physicists are daring to think the unthinkable – that black holes could connect us to another universe.

At their very heart, black holes are also where Einstein’s Theory of General Relativity is stretched in almost unimaginable ways, revealing black holes as the key to our understanding of the fundamentals of our universe and perhaps all other universes.

Join Professors Brian Cox and Jeff Forshaw in exploring our universe’s most mysterious inhabitants, how they are formed, why they are essential components of every galaxy, including our own, and what secrets they still hold, waiting to be discovered.

The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution. Such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. They are found to exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group, OB associations and as field stars. This book summarises the many advances in observational and theoretical work dedicated to blue straggler stars. Carefully edited extended contributions by well-known experts in the field cover all the relevant aspects of blue straggler stars research: Observations of blue straggler stars in their various environments; Binary stars and formation channels; Dynamics of globular clusters; Interpretation of observational data and comparison with models. The book also offers an introductory chapter on stellar evolution written by the editors of the book.

This 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.

Without interstellar dust, the Universe as we see it today would not exist. Yet at first we considered this vital ingredient merely an irritating fog that prevented a clear view of the stars and nebulae in the Milky Way and other galaxies. We now know that interstellar dust has essential roles in the physics and chemistry of the formation of stars and planetary systems, the creation of the building blocks of life, and in the movement of those molecules to new planets. This is the story in this book. After introducing the materials this interstellar dust is made of, the authors explain the range of sizes and shapes of the dust grains in the Milky Way galaxy and the life cycle of dust, starting from the origins of dust grains in stellar explosions through to their turbulent destruction. Later on we see the variety of processes in interstellar space involving dust and the events there that cause the dust to change in ways that astronomers and astrobiologists can use to indirectly observe those events. This book is written for a general audience, concentrating on ideas rather than detailed mathematics and chemical formulae, and is the first time interstellar dust has been discussed at an accessible level.

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.

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

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

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.

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.