Chemical Composition of the Carbon-rich, Extremely Metal Poor Star CS 29498-043: A New Class of Extremely Metal Poor Stars with Excesses of Magnesium and Silicon
Date
2002
Authors
Aoki, Wako
Norris, John
Ryan, Sean G
Beers, Timothy C
Anderson, W G
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Publishing
Abstract
We analyze a high-resolution, high signal-to-noise ratio spectrum of the carbon-rich, extremely metal poor star CS 29498-043, obtained with the Subaru Telescope High Dispersion Spectrograph. We find its iron abundance is extremely low ([Fe/H] = -3.7), placing it among the few stars known with [Fe/H] ≤ -3.5, while Mg and Si are significantly overabundant ([Mg/Fe] = +1.8 and [Si/Fe] = +1.1) compared with stars of similar metallicity without carbon excess. Overabundances of N and Al were also found. These characteristics are similar to the carbon-rich, extremely metal poor star CS 22949-037. Although the sample is small, our discovery of CS 29498-043 suggests the existence of a class of extremely metal poor stars with large excesses of C, N, Mg, and Si.
Description
Keywords
Keywords: Nuclear reactions, nucleosynthesis, abundances; Stars: abundances; Stars: carbon; Stars: individual (CS 29498-043); Stars: Population II
Citation
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Source
Astrophysical Journal, The
Type
Journal article