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Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. IV. The alpha-Element-Enhanced Metal-Poor Star BS16934-002

Wako Aoki·Satoshi Honda·Timothy C. Beers·Masahide Takada-Hidai·Nobuyuki Iwamoto·Nozomu Tominaga·Hideyuki Umeda·Ken'ichi Nomoto·John E. Norris·Sean G. Ryan
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Abstract

A detailed elemental abundance analysis has been carried out for the very metal-poor ([Fe/H]=-2.7) star BS16934-002, which was identified in our previous work as a star exhibiting large overabundances of Mg and Sc. A comparison of the abundance pattern of this star with that of the well-studied metal-poor star HD122563 indicates excesses of O, Na, Mg, Al, and Sc in BS16934-002. Of particular interest, no excess of C or N is found in this object, in contrast to CS22949-037 and CS29498-043, two previously known carbon-rich, extremely metal-poor stars with excesses of the alpha elements. No established nucleosynthesis model exists that explains the observed abundance pattern of BS16934-002. A supernova model, including mixing and fallback, assuming severe mass loss before explosion, is discussed as a candidate progenitor of BS16934-002.

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Wako Aoki, Satoshi Honda, Timothy C. Beers, Masahide Takada-Hidai, Nobuyuki Iwamoto, Nozomu Tominaga, Hideyuki Umeda, Ken'ichi Nomoto, John E. Norris, Sean G. Ryan. 2007-01-06. Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. IV. The alpha-Element-Enhanced Metal-Poor Star BS16934-002. https://doi.org/10.1086/512601

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