Angular Momentum And Mass Loss For Hot Stars

Author : L.A. Willson
Publisher : Springer Science & Business Media
ISBN 13 : 9400921055
Total Pages : 366 pages
Book Rating : 4.54/5 ( download)

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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.

Author : Luis A. Balona
Publisher : Springer Science & Business Media
ISBN 13 : 9401110301
Total Pages : 554 pages
Book Rating : 4.03/5 ( download)

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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.

Author : Anne Barbara Underhill
Publisher :
ISBN 13 :
Total Pages : 268 pages
Book Rating : 4.32/5 ( download)

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Download or read book The Origin of Nonradiative Heating/momentum in Hot Stars written by Anne Barbara Underhill and published by . This book was released on 1985 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : R. Stalio
Publisher : Springer Science & Business Media
ISBN 13 : 9400930291
Total Pages : 332 pages
Book Rating : 4.92/5 ( download)

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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.

Author : Wolf-Rainer Hamann
Publisher : Universitätsverlag Potsdam
ISBN 13 : 3940793337
Total Pages : 262 pages
Book Rating : 4.31/5 ( download)

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Download or read book Clumping in Hot-star Winds written by Wolf-Rainer Hamann and published by Universitätsverlag Potsdam. This book was released on 2008 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : M. Hack
Publisher : Springer Science & Business Media
ISBN 13 : 9401034052
Total Pages : 349 pages
Book Rating : 4.50/5 ( download)

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Download or read book Mass Loss from Stars written by M. Hack and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings from the Second Trieste Colloquium on Astrophysics, September 12-17, 1968

Author : Derek McNally
Publisher : Springer Science & Business Media
ISBN 13 : 9401133646
Total Pages : 616 pages
Book Rating : 4.47/5 ( download)

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Download or read book Reports on Astronomy written by Derek McNally and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: IAU Transactions are published as a volume corresponding to each General Assembly. Volume A is produced prior to the Assembly and contains Reports on Astronomy, prepared by each Commission President. The intention is to summarize the astronomical results that have affected the work of the Commission since the production of the previous Reports up to a time which is about one year prior to the General Assembly. Volume B is produced after the Assembly and contains accounts of Commission Meetings which were held, together with other material. The reports included in the present volume range from outline summaries to lengthy compilations and references.

Author : Santi Cassisi
Publisher : John Wiley & Sons
ISBN 13 : 3527665544
Total Pages : 506 pages
Book Rating : 4.49/5 ( download)

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Download or read book Old Stellar Populations written by Santi Cassisi and published by John Wiley & Sons. This book was released on 2013-08-29 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book discusses the theoretical path to decoding the information gathered from observations of old stellar systems. It focuses on old stellar systems because these are the fossil record of galaxy formation and provide invaluable information ont he evolution of cosmic structures and the universe as a whole. The aim is to present results obtained in the past few years for theoretical developments in low mass star research and in advances in our knowledge of the evolution of old stellar systems. A particularly representative case is the recent discovery of multiple stellar populations in galactic globular clusters that represents one of the hottest topics in stellar and galactic astrophysics and is discussed in detail. Santi Cassisi has authored about 270 scientific papers, 150 of them in peer-reviewed journals, and the title Evolution of Stars and Stellar Populations.

Author : International Astronomical Union. Symposium
Publisher : Cambridge University Press
ISBN 13 : 9780521889902
Total Pages : 716 pages
Book Rating : 4.01/5 ( download)

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Download or read book Cosmic Magnetic Fields (IAU S259) written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2009-06-11 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: IAU Symposium 259 presents the first interdisciplinary, comprehensive review of the role of cosmic magnetic fields, involving astronomers and physicists from across the community. Offering both theoretical and observational topics ranging from Earth's habitability to the origin of the universe, this is an invaluable summary for researchers and graduate students.

Author : Henny J. G. L. M. Lamers
Publisher : CRC Press
ISBN 13 : 9780750312790
Total Pages : 342 pages
Book Rating : 4.93/5 ( download)

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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.