Download or read book The Structure of Very Cool Helium rich White Dwarf Atmospheres written by Stylianos Petros Kapranidis and published by . This book was released on 1982 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book White Dwarf Atmospheres and Circumstellar Environments written by Donald W. Hoard and published by John Wiley & Sons. This book was released on 2012-09-19 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by selected astronomers at the forefront of their fields, this timely and novel book compiles the latest results from research on white dwarf stars, complementing existing literature by focusing on fascinating new developments in our understanding of the atmospheric and circumstellar environments of these stellar remnants. Complete with a thorough refresher on the observational characteristics and physical basis for white dwarf classification, this is a must-have resource for researchers interested in the late stages of stellar evolution, circumstellar dust and nebulae, and the future of our own Solar System.
Download or read book Model Atmospheres for Low Temperature Helium rich White Dwarfs written by Eric R. Peterson and published by . This book was released on 1992 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book White Dwarfs written by J. Isern and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of white dwarfs has been steadily growing during the last years and now is a mature field extending its influence over many others. Since white dwarfs are long lived objects, they can be used to obtain information about the history of the Galaxy. The simplicity of their structures enables them to act as precise particle physics laboratories and the extreme con ditions reached at their surfaces allow us to test the equation of state and to study the behavior of matter under conditions impossible to be reached in terrestrial laboratories. Nevertheless, white dwarfs are still challenging astrophysicists. Many questions, ranging from the determination of funda mental parameters to the evolution of their outer layers, are still waiting for a satisfactory answer. The European Workshop series on White Dwarfs started in 1974 as a con sequence of the effort and enthusiasm of Professor Volker Weidemann. The existing proceedings of these meetings, together with those corresponding to the lAU Colloquia held in Rochester (1979) and in Hanover (1988), provide a unique opportunity to follow the development of this field. We hope that the present volume will provide a representative snapshot of the state of the art in 1996. In this sense we are very indebted to all the participants that have sent their contributions according to the instructions (this clearly excludes everybody beyond three sigmas from the standards).
Download or read book The Atmospheric Structure and Chemical Composition of Cool Helium and Carbon White Dwarfs written by Thomas Cameron Grenfell and published by . This book was released on 1972 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Spectral Evolution of Cool Helium Atmosphere White Dwarfs Detailed Spectroscopic and Photometric Analysis of DZ Stars written by and published by . This book was released on 2007 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a detailed analysis of a large spectroscopic and photometric sample of DZ white dwarfs based on our latest model atmosphere calculations. We revise the atmospheric parameters of the trigonometric parallax sample of Bergeron, Leggett, & Ruiz (12 stars) and analyze 147 new DZ white dwarfs discovered in the SDSS. The inclusion of metals and hydrogen in our model atmosphere calculations leads to different atmospheric parameters than those derived from pure helium models. Calcium abundances are found in the range from log (Ca/He) = -12 to -8. We also find that fits of the coolest objects show peculiarities, suggesting that our physical models may not correctly describe the conditions of high atmospheric pressure encountered in the coolest DZ stars. We find that the mean mass of the 11 DZ stars with trigonometric parallaxes is significantly lower than that obtained from pure helium models and in much better agreement with the mean mass of other types of white dwarfs. We determine hydrogen abundances for 27% of the DZ stars in our sample, while only upper limits are obtained for objects with low-S/N spectroscopic data. We confirm with a high level of confidence that the accretion rate of hydrogen is at least 2 orders of magnitude smaller than that of metals (and up to 5 in some cases) to be compatible with the observations. We find a correlation between the hydrogen abundance and the effective temperature, suggesting for the first time empirical evidence of a lower temperature boundary for the hydrogen screening mechanism. Finally, we speculate on the possibility that the DZA white dwarfs could be the result of the convective mixing of thin hydrogen rich atmospheres with the underlying helium convection zone.
Download or read book White Dwarf Atmospheres and Circumstellar Environments written by Donald W. Hoard and published by John Wiley & Sons. This book was released on 2012-09-19 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by selected astronomers at the forefront of their fields, this timely and novel book compiles the latest results from research on white dwarf stars, complementing existing literature by focusing on fascinating new developments in our understanding of the atmospheric and circumstellar environments of these stellar remnants. Complete with a thorough refresher on the observational characteristics and physical basis for white dwarf classification, this is a must-have resource for researchers interested in the late stages of stellar evolution, circumstellar dust and nebulae, and the future of our own Solar System.
Download or read book The structure of white dwarf atmospheres written by Yoichi Terashita and published by . This book was released on 1966 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structure of White dwarf Atmospheres written by Yoichi Terashita and published by . This book was released on 1966 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Blanketed model atmospheres for cool hydrogen rich white dwarfs written by Rainer Wehrse and published by . This book was released on 1971 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Literature 1991 Part 2 written by Astronomisches Rechen-Institut and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 1592 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Astronomy and Astrophysics Abstracts" appearing twice a year has become oneof the fundamental publications in the fields of astronomy, astrophysics andneighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. The abstrats are classified under more than a hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world.
Download or read book An H Spectroscopic Survey of Cool Helium rich C2 and DC White Dwarfs written by Frank H. Yackovich and published by . This book was released on 1983 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Asteroseismology written by Pere L. Pallé and published by Cambridge University Press. This book was released on 2014-01-13 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our understanding of stars has grown significantly due to recent advances in asteroseismology, the stellar analog of helioseismology, the study of the Sun's acoustic wave oscillations. Using ground-based and satellite observatories to measure the frequency spectra of starlight, researchers are able to probe beneath a star's surface and map its interior structure. This volume provides a wide-ranging and up-to-date overview of the theoretical, experimental and analytical tools for carrying out front-line research in stellar physics using asteroseismological observations, tools and inferences. Chapters from seven eminent scientists in residence at the twenty-second Canary Islands Winter School of Astrophysics examine the interior of our Sun relative to data collected from distant stars, how to measure the fundamental parameters of single field stars, diffusion processes, and the effects of rotation on stellar structures. The volume also provides detailed treatments of modeling and computing programs, providing astronomers and graduate students a practical, methods-based guide.
Download or read book An Hydrogen alpha Spectroscopic Survey of Cool Helium rich C2 and DC White Dwarfs written by and published by . This book was released on 1982 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An H alpha Spectroscopic Survey of Cool Helium rich C2 and DC White Dwarfs written by Frank H. Yackovich and published by . This book was released on 1982 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Helium on a White Dwarf Atmosphere written by Lawrence Nicola and published by . This book was released on 1959 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
