Download or read book Explaining Lithium Enriched Red Giant Branch Stars written by Claudia Aguilera-Gómez and published by Springer. This book was released on 2018-11-28 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis provides new insights into the seemingly anomalous ubiquity of lithium-rich red giant stars. The theory of stellar evolution, one of the most successful models of modern astrophysics, predicts that red giant stars should display negligible levels of lithium (Li) on their surfaces. However, Li-rich giants, defined as those showing more than three times the Li content of the Sun, are found everywhere astronomers look in apparent defiance of established theory. The author addresses this problem, analyzing the different possible explanations for such an anomaly, which include interaction with a binary companion, the production of Li in the interior of the star with its subsequent transport to stellar exteriors, and the stellar interaction with planets. The author focuses on this last possibility, where the Li enrichment may be due to the ingestion of planets or brown dwarfs as the stars in question grew in size while becoming giants. She shows that this process is indeed able to explain an important fraction of giants with Li levels above the three times solar threshold, but that some other mechanism is needed to explain the remaining fraction. While this is an important discovery in its own right, the result that makes this thesis groundbreaking is its demonstration that the threshold between Li-normal and Li-rich is mass dependent rather than a fixed proportion of the Sun’s content. This corrects a fundamental misapprehension of the phenomenon and opens up a new framework in which to understand and solve the problem. Finally, the author presents interesting observational applications and samples with which to test this new approach to the problem of Li enrichment in giants.
Download or read book Chemical Abundances and Mixing in Stars in the Milky Way and its Satellites written by S. Randich and published by Springer Science & Business Media. This book was released on 2006-09-25 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings covers topics from chemical abundances in the different components of the Milky Way and in local group galaxies, via observational and theoretical papers on mixing in stars to big bang nucleosynthesis and galaxy formation and evolution. Like all volumes in the series ESO Astrophysics Symposia, this one gives a comprehensive overview of the forefront of research in this subject. It is a valuable reference for both students and researchers.
Download or read book Astronomical Applications of Astrometry written by M. A. C. Perryman and published by Cambridge University Press. This book was released on 2009 with total page 695 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative account of the contributions to science made by the Hipparcos satellite, for astronomers, astrophysicists and cosmologists.
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 Origins of Life written by Vlado Valkovic and published by CRC Press. This book was released on 2021-11-09 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary purpose of this book is to prepare the ground for coordinated efforts aiming to answer the question: where and when life originated. The appearance of life involves three successive stages: i) the formation of chemical elements and their combination to simple molecules, which is the concern of physicists; ii) the evolution of organized complexity in biomolecules and their reactions, which falls within the field of chemistry; iii) the onset of Darwinian evolution after the appearance of the first cell-like structure, which is studied by biologists. This book focuses on the first two steps of this process with chapters exploring topics such as chemical element abundances; galaxies, galactic magnetic fields and cosmic rays; galactic chemical evolution. Key Features: Contains extensive lists of reference and additional reading. Includes new hypotheses concerning the origin of life. Combines consideration from nuclear physics, astrophysics, astro- and geochemistry. Despite its interdisciplinary nature, this book remains accessible to nonexperts, and would be a valuable companion for both experts and laypeople.
Download or read book Chemical Abundances in the Universe written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2010 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: Session I : Primordial nucleosynthesis and the first stars in the Universe -- Session II : First stars in the Galaxy -- Session III : Chemical abundances in the high red-shift Universe -- Session IV : Chemical abundance constraints on mass assembly and star formation in local galaxies and the Milky Way -- Session V : Extrasolar planets: the chemical abundance connection -- Session VI : Abundance surveys and projects in the era of future large telescopes.
Download or read book Civil Services Chronicle September 2020 written by Mr. NN OJha and published by CHRONICLE PUBLICATIONS PVT LTD. This book was released on 2020-08-15 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The No.1 Magazine for IAS Aspirants Since 1990
Download or read book Astrophysics and Space Science written by L.B.F.M. Waters and published by Springer Science & Business Media. This book was released on 1998-08-31 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: This conference proceedings contains review papers and contributed papers discussing early results from the Infrared Space Observatory (ISO) on the subject of stellar evolution. Three topics have been emphasized in the book: young stellar objects and Vega-type stars, circumstellar matter of massive stars, and late stages of stellar evolution. The very rich harvest of new results from ISO is demonstrated by the many discoveries of new solid state and molecular bands in the spectra of stars and circumstellar shells, and by spectacular images of circumstellar and interstellar matter. The book is intended for professional astronomers and students.
Download or read book Light Elements in the Universe IAU S268 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2010-05-13 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: IAU Symposium 268 presents an overview of the most recent observational and theoretical research on the formation and evolution of light elements in the Universe: H, He, Li, Be, B, and their isotopes. Astrophysicists from a variety of subfields discuss recent developments that will improve our understanding of the light elements and provide important clues to stellar and galactic evolution, Big Bang nucleosynthesis, and cosmology. Striking observational progress has been achieved recently through the advent of next generation ground- and space-based telescopes, such as the cosmic microwave background experiments that allow the accurate determination of the baryon density of the Universe. New theoretical breakthroughs in describing stellar interiors and the chemical evolution of complex systems and the remaining challenges in this field are also addressed. This critical review is a useful resource for all those interested in the chemical evolution of the Universe.
Download or read book Nuclear Reactions of Astrophysical Interest written by Scilla Degl’Innocenti and published by Frontiers Media SA. This book was released on 2021-07-29 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astronomy Reports written by and published by . This book was released on 1999 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Origin and Evolution of the Elements Volume 4 Carnegie Observatories Astrophysics Series written by Andrew McWilliam and published by Cambridge University Press. This book was released on 2004-09-23 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Carnegie volume discusses the origin and evolution of elements in our galaxy and others.
Download or read book From Lithium to Uranium IAU S228 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2005 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of IAU S228 detailing progress in our knowledge of element production and evolution.
Download or read book Star Clusters written by B.W. Carney and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Star clusters are at the heart of astronomy, being key objects for our understanding of stellar evolution and galactic structure. Observations with the Hubble Space Telescope and other modern equipment have revealed fascinating new facts about these galactic building blocks. This book provides two comprehensive and up-to-date, pedagogically designed reviews on star clusters by two well-known experts in the field. Bruce Carney presents our current knowledge of the relative and absolute ages of globular clusters and the chemical history of our Galaxy. Bill Harris addresses globular clusters in external galaxies and their use as tracers of galaxy formation and cosmic distance indicators. The book is written for graduate students as well as professionals in astronomy and astrophysics.
Download or read book Literature 1997 Part 1 written by Astronomisches Rechen-InstitutARI and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. Two volumes are scheduled to appear per year. Volume 67 records 10,903 papers covering besides the classical fields of astronomy and astrophysics such matters as space flights related to astronomy, lunar and planetary probes and satellites, meteorites and interplanetary matter, X rays and cosmic rays, quasars and pulsars. The abstracts are classified under more than one hundred subject categories thus permitting quick surveying of the bulk of material published on the same topic within six months. For instance, this volume records 119 papers on minor planets, 155 papers on supernovae, and 554 papers on cosmology.
Download or read book 1997 Pacific Rim Conference on Stellar Astrophysics written by Kwing-Lam Chan and published by . This book was released on 1998 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deep Mixing in Globular cluster Red Giants written by P. A. Denissenkov and published by Cambridge Scientific Publishers. This book was released on 2004 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents and reviews the results of studies on subjects closely related to the problems of abundance anomalies in globular clusters and covers in particular the problem of deep mixing in globular-cluster red giants and describes a diffusion model and a mechanism for extra mixing in red giants. The author traces the development of scenarios to explain the origin of star-to star variations in elemental abundances in globular clusters: primordial nucleosynthesis and mixing and the background to the proposal of a combined scenario and a model for the chemical evolution of globular clusters. This review provides a useful reference text for graduates and researchers in astrophysics.
