Results 351 to 360 of about 895,436 (365)

Stellar and Solar Abundances

Space Science Reviews, 1973
Recent spectroscopic results on stellar and solar abundances are reviewed with special reference to (a) Standard abundance distribution (Sun, hot stars, diffuse nebulae); (b) Abundance peculiarities related to stellar evolution (red giants showing results of H-burning and s-process, peculiar and metallic-lined stars); and (c) Population effects that ...
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Automated stellar abundance analysis

Proceedings of the International Astronomical Union, 2013
AbstractThe advent of Milky Way high-resolution spectroscopic surveys has brought our attention to the importance of precise chemical abundance measurements to disentangle the stellar population puzzle of the Galaxy. Moreover, automated stellar parameters are the bedrock of Galactic spectroscopic surveys science.
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Nucleosynthesis and future stellar abundance determinations

EAS Publications Series, 2004
AbstractFor Abstract see ChemInform Abstract in Full Text.
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Element Abundances in Stellar Coronae

1996
About two years ago, the intrigue of the solar “FIP Effect”—that coronal abundances of elements with a low FIP (≲ 10 eV; e.g Fe, Mg, Si, Ca) are observed to be enhanced relative to those of high FIP elements (≳ 10 eV; e.g. O, Ne, S; see e.g. the review by Meyer 1993)—prompted us to study stellar coronal abundances based on new EUV spectra obtained with
J. J. Drake, J. M. Laming, K. G. Widing
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Stellar chemical abundances with the GHRS

Physica Scripta, 1996
The accurate quantitative analysis of high resolution ultraviolet spectra of ultra-sharp-lined early-type, chemically peculiar stars, obtained with the Goddard High Resolution spectrograph on the Hubble Space Telescope, has been made possible by the synergism between state-of-the-art astro-physics and state-of-the-art atomic spectroscopy. We illustrate
David S Leckrone, Sveneric Johansson, Glenn M Wahlgren, Charles R Proffitt, Tomas Brage   +4 more
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Abundance measurements in stellar environments

AIP Conference Proceedings, 2014
Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit.
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From Stellar Spectra to Abundances

Astrophysics and Space Science, 2001
The current techniques of stellar abundances determination from high resolution spectra are discussed, and the related uncertainties arising from the analysis are examined. These involve the observational uncertainties but also physical data, and atmosphere models accuracy. This critical assessment is then used to shed light on the controversial [O/Fe]
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Abundance ratios in quasi-stellar objects

Astrophysics and Space Science, 1977
Relative abundances of carbon and aluminium with respect to silicon have been calculated in the QSOs PHL957, PKS0237-23, 1331+170, 3C191 and M132. Relative abundance of Fe with respect to Mg has been also calculated in the QSOs 1331+170 and PHL938. The ratiosN(C)/N(Si),N(Al)/N(Si) andN(Fe)/N(Mg) in QSOs considered as a class are (5.5±1.6), (0.13±0.03 ...
R. K. Thakur, P. K. Mishra
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Stellar nucleosynthesis and galactic abundances

AIP Conference Proceedings, 2001
Galactic abundances are neither constant in time nor do they evolve in a simple fashion, e.g., by an enrichment of heavy elements in constant relative proportions. Instead, their evolution in space and time reflects the history of star formation and the lifetimes of the diverse contributing stellar objects.
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Elemental abundances for stellars-process studies

Astrophysics and Space Science, 1987
Nuclear reaction network calculations of heavy element enhancements are tabulated for different values of the mean neutron exposure τ0. These tables are useful for comparison with observeds-process abundance patterns which appear to span a wide range in τ0.
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