Download or read book Pulsation and Mass Loss in Stars written by R. Stalio and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stellar mass loss is an essential part of the cycling of material from the interstellar medium into stars and back, and must be understood if we are to model processes on galactic to cosmological scales. The study of stellar winds and the effects of stellar mass loss has reached a particularly exciting stage where observational capabilities are increasingly able to provide interesting constraints on models and theories. Recent resu1ts from theoretical and observational work for both hot and cool stars with substantial winds have led to the suggestion that a combination of pulsation with other mechanisms makes for particularly efficient mass loss from stars. This provided the original motivation for the organization of this workshop. The conference was organized along relatively conventional lines according to the types of objects being scrutinized. However the true unity of the proceedings comes from the interplay of the mechanisms involved. For example, for the cool, luminous Mira variables, pulsation leads to shock waves that extend the atmosphere, enhancing dust formation; radiation pressure on dust drives the wind, cooling the atmosphere and in some cases suppressing the shocks. Similarly for the Be stars, both pulsation (in this case, non-radial) and radiation pressure (due to UV resonance lines) are expected to be important, and this expectation is at least qualitatively borne out by the observations.
Download or read book Pulsation Rotation and Mass Loss in Early Type Stars written by Luis A. Balona and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this Symposium, researchers specializing in pulsation, rotation, magnetic fields and stellar winds are brought together for the first time in order to broaden our understanding of O and B stars. Thanks to advances in digital spectroscopy, new types of pulsating B stars have been discovered. The pulsations can be understood in terms of the recent revision of metal opacities, but the effects of rapid rotation and magnetic fields need further study. Observations in the UV and X-ray regions demonstrate that many B and Be stars show other activity, besides pulsation which is not yet understood. The reason for the enhanced mass loss in Be stars is a question which dominates the Symposium and which remains unanswered, although it is surely to be found in activity at or near the photosphere coupled with rotation. It is shown that the geometry of the circumstellar envelopes around Be stars is indeed a flattened disk as they can now be optically resolved. The variability of radiatively-driven winds from O and B stars are likely related to the rotation of the star. This underlines the central theme of the book: that the various phenomena seen in these stars cannot be studied in isolation.
Download or read book Angular Momentum and Mass Loss for Hot Stars written by L.A. Willson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental unsolved problems of stellar astrophysics include the effects of angular momentum on stellar structure and evolution, the nature and efficiency of the processes by which angular momentum is redistributed within and lost from stars, and the role that stellar rotation plays in enhancing or driving stellar mass loss. There appears to be a qualitative change in the nature and efficiency of these mechanisms near spectral type FO: hotter (more massive) stars typically retain more angular momentum at least until they reach the main sequence, while cooler stars typically spin down quickly. For the hotter stars, recent work suggests a strong link between the type of pulsation behavior, the mass loss rates, and the rotation velocity. If the same mechanisms are able to drive mass loss from the main sequence A stars, as has recently been proposed, then the current interpretations of a number of observations will be drastically affected: e. g. the ages of clusters may be incorrect by up to a factor of two, and the surface abundances of isotopes of He, Li and Be may no longer give constraints on cosmological nucleosynthesis. There are also effects on the evolution of the abundances of elements in the interstellar medium and on the general evolution of populations of stars. Thus the questions of the mechanisms of angular momentum and mass loss of stars more massive than the sun is important not only for stellar studies but for the foundations of much of modern astrophysics.
Download or read book Understanding Stellar Evolution written by Henny J. G. L. M. Lamers and published by CRC Press. This book was released on 2018-02-28 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Understanding Stellar Evolution' is based on a series of graduate-level courses taught at the University of Washington since 2004, and is written for physics and astronomy students and for anyone with a physics background who is interested in stars. It describes the structure and evolution of stars, with emphasis on the basic physical principles and the interplay between the different processes inside stars such as nuclear reactions, energy transport, chemical mixing, pulsation, mass loss, and rotation. Based on these principles, the evolution of low- and high-mass stars is explained from their formation to their death. In addition to homework exercises for each chapter, the text contains a large number of questions that are meant to stimulate the understanding of the physical principles. An extensive set of accompanying lecture slides is available for teachers in both Keynote(R) and PowerPoint(R) formats.
Download or read book Mass Losing Pulsating Stars and their Circumstellar Matter written by Y. Nakada and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Editing the proceedings of a scientific meeting is not an easy task. Sometimes people who give an excellent talk do not send the manuscript by the deadline. However, this time, thanks to the punctuality of all the participants, we have this excellent volume for the workshop on mass losing pulsating stars and their circumstellar matter prepared in time. Almost all of the oral presentations including the summary are collected in this volume. We regret that we cannot put in this volume a few posters that we failed to receive before the editorial work. The workshop was planned as a small meeting with less than fifty attendants because the city of Sendai was far from the most of the active institutions. However, the number of submitted papers exceeded the SOC's expectation; many interesting contributions had to be scheduled in the poster session. Still, the oral sessions were so tight that many participants might have felt frustrated for the shortage of discussions. The organizers of the workshop have to apologize to the attendants for the inconvenience caused from such a happy underestimate about the size of the workshop.
Download or read book Pulsating Stars written by Márcio Catelan and published by John Wiley & Sons. This book was released on 2014-12-29 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book surveys our understanding of stars which change in brightness because they pulsate. Pulsating variable stars are keys to distance scales inside and beyond the Milky Way galaxy. They test our understanding not only of stellar pulsation theory but also of stellar structure and evolution theory. Moreover, pulsating stars are important probes of the formation and evolution of our own and neighboring galaxies. Our understanding of pulsating stars has greatly increased in recent years as large-scale surveys of pulsating stars in the Milky Way and other Local Group galaxies have provided a wealth of new observations and as space-based instruments have studied particular pulsating stars in unprecedented detail.
Download or read book Understanding Stellar Evolution written by Henny J. G. L. M. Lamers and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Understanding Stellar Evolution is based on a series of graduate-level courses taught at the University of Washington since 2004, and is written for physics and astronomy students and for anyone with a physics background who is interested in stars. It describes the structure and evolution of stars, with emphasis on the basic physical principles and the interplay between the different processes inside stars such as nuclear reactions, energy transport, chemical mixing, pulsation, mass loss, and rotation. Based on these principles, the evolution of low- and high-mass stars is explained from their formation to their death. In addition to homework exercises for each chapter, the text contains a large number of questions that are meant to stimulate the understanding of the physical principles. An extensive set of accompanying lecture slides is available for teachers in both Keynote and PowerPoint formats."--Source : résumé de l'éditeur.
Download or read book Communications in Asteroseismology 2009 written by Michael Breger and published by Austrian Academy of Sciences. This book was released on 2009 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This colloquium was the 38th Li'ege International Astrophysical Colloquium (38thLIAC -http://www.ago.ulg.ac.be/APub/Colloques/Liac38) it was also held under the auspices of the European Helio- and Asteroseismology Network (HELAS - http://www.helas-eu.org/), the CoRoT Evolution and Seismic Tools Activity (CoRoT/ESTA - http://www.astro.up.pt/esta/) and the Belgian Asteroseismology Group (BAG - http://www.asteroseismology.be). The first part of the conference was devoted to the internal structure of massive stars with session 1 dealing with the theoretical aspects of non standard physical processes while session 2 presented the challenges met in stellar modelling when introducing these physical processes. Session 3 was a state of the art in atmospheres, mass loss and stellar winds in massive stars. Session 4 presented the pulsation observations in massive stars while session 5 discussed the asteroseismic signatures of the physical processes involved in their internal structure. A final session 6 was essentially focused on the interpretation of the asteroseismic observations of ground-based, MOST and CoRoT targets.
Download or read book New Perspectives on Stellar Pulsation and Pulsating Variable Stars written by James M. Nemec and published by Cambridge University Press. This book was released on 1993-10-21 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can the interior of the Sun, white dwarfs and other stars be studied by stellar seismology? What can Doppler imaging tell us about high-degree pulsations? What impact are CCD and infrared observations having on extending the Cepheid and RR Lyrae distance scale? And how are other classes of pulsators providing independent checks of the distance scale? These and many other critical questions are answered in this timely review of the dramatic advances made in pulsating star research in the last decade. This survey collects together more than thirty comprehensive reviews and over one hundred summaries of research papers from the 139th IAU Colloquium, held in Victoria, British Columbia. Together these cover all aspects of recent developments in the field of variable star research and preview some of the exciting advances anticipated for the next decade. This volume provides an essential review for graduate students and researchers.
Download or read book Asymptotic Giant Branch Stars written by Harm J. Habing and published by Springer Science & Business Media. This book was released on 2004 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with stars during a short episode before they undergo a ma jor, and fatal, transition. Soon the star will stop releasing nudear energy, it will become a planetary nebula for abrief but poetic moment, and then it will turn into a white dwarf and slowly fade out of sight. Just before this dramatic change begins the star has reached the highest luminosity and the largest diameter in its existence, and while it is a star detectable in galaxies beyond the Local Group, its structure contains already the inconspicuous white dwarf it will become. It is called an "asymptotic giant branch star" or "AGB star". Over the last 30 odd years AGB stars have become a topic of their own although individual members of this dass had already been studied for cen turies without realizing what they were. In the early evolution, so called "E-AGB"-phase, the stars are a bit bluer than, but otherwise very similar to, what are now called red giant branch stars (RGB stars). It is only in the sec ond half of their anyhow brief existence that AGB stars differ fundamentally from RGB stars.
Download or read book Stellar Structure and Evolution written by Rudolf Kippenhahn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The text presents an overview of the models developed to explain the stability, dynamics and evolution of the stars, and great care is taken to detail the various stages in a star's life. The authors have succeeded in producing a unique text based on their own pioneering work in stellar modeling. Since its publication, this textbook has come to be considered a classic by both readers and teachers in astrophysics. This study edition is intended for students in astronomy and physics alike.
Download or read book Structure and Evolution of Single Stars written by James MacDonald and published by Morgan & Claypool Publishers. This book was released on 2015-12-01 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structure and Evolution of Single Stars: An introduction is intended for upper-level undergraduates and beginning graduates with a background in physics. Following a brief overview of the background observational material, the basic equations describing the structure and evolution of single stars are derived. The relevant physical processes, which include the equation of state, opacity, nuclear reactions and neutrino losses are then reviewed. Subsequent chapters describe the evolution of low-mass stars from formation to the final white dwarf phase. The final chapter deals with the evolution of massive stars.
Download or read book Stellar Pulsation Nonlinear Studies written by Mine Takeuti and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stellar pulsations provide a complex system in stars. This complexity is studied by analyzing the non-sinusoidal, semi-regular, or irregular light curves. This unique volume summarizes the application of recent theoretical results obtained from stellar pulsation studies. In addition, the latest developments in hydrodynamic simulations are discussed. A historical sketch of the study of beat Cepheids, first known for their variable amplitudes, is given as an introduction to the book. This introduction clearly demonstrates how complicated the study of variable stars can be, and therefore challenges and invites the reader to study the entire book.
Download or read book Time dependent Mass Loss from Hot Stars with and Without Radiative Driving written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical hydrodynamics code is used to investigate two aspects of the winds of hot stars. The first is the question of the instability of the massive radiatively-driven wind of an O star that is caused by the line shape mechanism: modulation of the radiation force by velocity fluctuations. The evolution of this instability is studied in a model O star wind, and is found, /ital modulo/ some numerical uncertainty, to lead to wave structures that are compatible with observations of wind instabilities. The other area of investigation is of main-sequence B star winds. Attempts were made to simulate a radiatively-driven and a pulsation-driven wind in a B star, but in each case the wind turned out to be very weak. It is argued that the pulsation-driven wind model is not likely to apply to B stars. 28 refs., 11 figs.
Download or read book New Worlds New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
Download or read book Introduction to Stellar Winds written by Henny J. G. L. M. Lamers and published by Cambridge University Press. This book was released on 1999-06-17 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first comprehensive introduction to the observations and theories of stellar winds; a long-awaited graduate textbook, written by two founders of the field.
Download or read book Stellar Physics written by G.S. Bisnovatyi-Kogan and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Stellar Physics" is a rather unique book in the growing literature on star formation and evolution. Not only does the author, a leading expert in the field, give a very thorough description of the current knowledge about stellar physics, but he handles with equal care the many problems that this field of research still faces. A bibliography with well over 650 entries makes this book an unparalleled source of references. "Stellar Evolution and Stability" is the second volume and can be read, as can the first volume, as a largely independent work. It traces in great detail the evolution of the protostar towards the main sequence and beyond this to the last stage of stellar evolution, with the corresponding vast range from white dwarfs to the mighty supernovae explosions and blackhole formation. The book concludes with special chapters on the dynamical, thermal and pulsing stability of stars.
