Atomic Diffusion in Stars

Atomic Diffusion in Stars PDF Author: Georges Michaud
Publisher: Springer
ISBN: 3319198548
Category : Science
Languages : en
Pages : 333

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Book Description
The authors give an overview of atomic diffusion as applied to all types of stars, showing where it plays an essential role and how it can be implemented in modelling. Part I describes the tools that are required to include atomic diffusion in models of stellar interiors and atmospheres. An important role is played by the gradient of partial radiative pressure, or radiative acceleration, which is usually neglected in stellar evolution. In Part II, the authors systematically review the contribution of atomic diffusion to each evolutionary step. The dominant effects of atomic diffusion are accompanied by more subtle effects on a large number of structural properties throughout evolution. The goal of this book is to provide the means for the astrophysicist or graduate student to evaluate the importance of atomic diffusion in a given star. A fundamental physical process, atomic diffusion can significantly affect the superficial abundances of stars and/or their evolution. This guide includes all the information needed to take proper account of atomic diffusion's impact.

Atomic Diffusion in Stars

Atomic Diffusion in Stars PDF Author: Georges Michaud
Publisher: Springer
ISBN: 3319198548
Category : Science
Languages : en
Pages : 333

Get Book Here

Book Description
The authors give an overview of atomic diffusion as applied to all types of stars, showing where it plays an essential role and how it can be implemented in modelling. Part I describes the tools that are required to include atomic diffusion in models of stellar interiors and atmospheres. An important role is played by the gradient of partial radiative pressure, or radiative acceleration, which is usually neglected in stellar evolution. In Part II, the authors systematically review the contribution of atomic diffusion to each evolutionary step. The dominant effects of atomic diffusion are accompanied by more subtle effects on a large number of structural properties throughout evolution. The goal of this book is to provide the means for the astrophysicist or graduate student to evaluate the importance of atomic diffusion in a given star. A fundamental physical process, atomic diffusion can significantly affect the superficial abundances of stars and/or their evolution. This guide includes all the information needed to take proper account of atomic diffusion's impact.

Stellar Astrophysics

Stellar Astrophysics PDF Author: Roger John Tayler
Publisher: Taylor & Francis Group
ISBN: 9780750302005
Category : Science
Languages : en
Pages : 356

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Book Description
Stellar Astrophysics contains a selection of high-quality papers that illustrate the progress made in research into the structure and evolution of stars. Senior undergraduates, graduates, and researchers can now be brought thoroughly up to date in this exciting and ever-developing branch of astronomy.

Transformations of Materials

Transformations of Materials PDF Author: Dimitri D Vvedensky
Publisher: Morgan & Claypool Publishers
ISBN: 1643276204
Category : Science
Languages : en
Pages : 184

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Book Description
Phase transformations are among the most intriguing and technologically useful phenomena in materials, particularly with regard to controlling microstructure. After a review of thermodynamics, this book has chapters on Brownian motion and the diffusion equation, diffusion in solids based on transition-state theory, spinodal decomposition, nucleation and growth, instabilities in solidification, and diffusionless transformations. Each chapter includes exercises whose solutions are available in a separate manual. This book is based on the notes from a graduate course taught in the Centre for Doctoral Training in the Theory and Simulation of Materials. The course was attended by students with undergraduate degrees in physics, mathematics, chemistry, materials science, and engineering. The notes from this course, and this book, were written to accommodate these diverse backgrounds.

Astronomy and Astrophysics - Volume II

Astronomy and Astrophysics - Volume II PDF Author: Oddbjørn Engvold Bozena Czerny, John Lattanzio and Rolf Stabell
Publisher: EOLSS Publications
ISBN: 1780210019
Category :
Languages : en
Pages : 488

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Book Description


Physics, Formation and Evolution of Rotating Stars

Physics, Formation and Evolution of Rotating Stars PDF Author: Andre Maeder
Publisher: Springer Science & Business Media
ISBN: 3540769498
Category : Science
Languages : en
Pages : 832

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Book Description
Rotation is ubiquitous at each step of stellar evolution, from star formation to the final stages, and it affects the course of evolution, the timescales and nucleosynthesis. Stellar rotation is also an essential prerequisite for the occurrence of Gamma-Ray Bursts. In this book the author thoroughly examines the basic mechanical and thermal effects of rotation, their influence on mass loss by stellar winds, the effects of differential rotation and its associated instabilities, the relation with magnetic fields and the evolution of the internal and surface rotation. Further, he discusses the numerous observational signatures of rotational effects obtained from spectroscopy and interferometric observations, as well as from chemical abundance determinations, helioseismology and asteroseismology, etc. On an introductory level, this book presents in a didactical way the basic concepts of stellar structure and evolution in "track 1" chapters. The other more specialized chapters form an advanced course on the graduate level and will further serve as a valuable reference work for professional astrophysicists.

The A-Star Puzzle (IAU S224)

The A-Star Puzzle (IAU S224) PDF Author: International Astronomical Union. Symposium
Publisher: Cambridge University Press
ISBN: 9780521850186
Category : Science
Languages : en
Pages : 544

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Book Description
Explores some of the less well understood physical processes involved in the modeling of stars.

Amplitude Modulation of Pulsation Modes in Delta Scuti Stars

Amplitude Modulation of Pulsation Modes in Delta Scuti Stars PDF Author: Dominic M. Bowman
Publisher: Springer
ISBN: 3319666495
Category : Science
Languages : en
Pages : 217

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Book Description
This outstanding thesis by Dominic Bowman provides a thorough investigation of long-standing questions as to whether amplitude modulation is astrophysical, whether it offers insights into pulsating stars, and whether simple beating of modes with stable amplitudes is unrecognised because of a lack of frequency resolution. In this thesis, the author studied a uniform sample of 983 delta Scuti stars—the most common type of main-sequence heat engine pulsator—that were observed nearly continuously for 4 years at stunning photometric precision of only a few parts per million by the Kepler space mission. With no mission planned to supersede the Kepler 4-year data set, this thesis will stand as the definitive study of these questions for many years. With revolutionary photometric data from the planet-hunting Kepler space mission, asteroseismic studies have been carried out on many hundreds of main-sequence solar-type stars and about 10,000 red giants. It is easy to understand why those stochastically driven stars have highly variable amplitudes. Over much of the rest of the Hertzsprung–Russell (HR) diagram, stellar pulsations are driven by heat mechanisms, which are much more regular than the stochastic driving in solar-like pulsators. Yet for decades, amplitude and frequency modulation of pulsation modes have been observed in almost all types of heat-driven pulsating stars. The author shows that the amplitude and frequency modulation are astrophysical, and he has investigated their implications and prospects to provide new insights into the delta Scuti stars and the many other types of heat-engine pulsators across the HR diagram.

Interior Modelling of Massive Stars in Multiple Systems

Interior Modelling of Massive Stars in Multiple Systems PDF Author: Cole Johnston
Publisher: Springer Nature
ISBN: 3030663108
Category : Science
Languages : en
Pages : 198

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Book Description
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.

Stars and Stellar Processes

Stars and Stellar Processes PDF Author: M. W. Guidry
Publisher: Cambridge University Press
ISBN: 1107197880
Category : Science
Languages : en
Pages : 573

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Book Description
Presents the physics of stars in relation to modern topics such as neutrino oscillations, supernovae, black holes, and gravitational waves.

Evolution of Stars and Stellar Populations

Evolution of Stars and Stellar Populations PDF Author: Maurizio Salaris
Publisher: John Wiley & Sons
ISBN: 9780470092224
Category : Science
Languages : en
Pages : 386

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Book Description
Evolution of Stars and Stellar Populations is a comprehensive presentation of the theory of stellar evolution and its application to the study of stellar populations in galaxies. Taking a unique approach to the subject, this self-contained text introduces first the theory of stellar evolution in a clear and accessible manner, with particular emphasis placed on explaining the evolution with time of observable stellar properties, such as luminosities and surface chemical abundances. This is followed by a detailed presentation and discussion of a broad range of related techniques, that are widely applied by researchers in the field to investigate the formation and evolution of galaxies. This book will be invaluable for undergraduates and graduate students in astronomy and astrophysics, and will also be of interest to researchers working in the field of Galactic, extragalactic astronomy and cosmology. comprehensive presentation of stellar evolution theory introduces the concept of stellar population and describes "stellar population synthesis" methods to study ages and star formation histories of star clusters and galaxies presents stellar evolution as a tool for investigating the evolution of galaxies and of the universe in general