Ther‐Process–enriched Low‐Metallicity Giant HD 115444
Author(s) -
Jenny Westin,
C. Sneden,
B. Gustafsson,
J. J. Cowan
Publication year - 2000
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/308407
Subject(s) - physics , nucleosynthesis , astrophysics , metallicity , stars , spectral line , red giant , o type main sequence star , giant star , line (geometry) , stellar atmosphere , astronomy , galactic halo , halo , galaxy , k type main sequence star , t tauri star , geometry , mathematics
New high resolution, very high signal-to-noise spectra of ultra-metal-poor(UMP) giant stars HD 115444 and HD 122563 have been gathered with theHigh-Resolution Echelle Spectrometer of the McDonald Observatory 2.7mTelescope. With these spectra, line identification and model atmosphereanalyses have been conducted, emphasizing the neutron-capture elements. Twentyelements with Z > 30 have been identified in the spectrum of HD 115444. Thisstar is known to have overabundances of the neutron-capture elements, but ithas lacked a detailed analysis necessary to compare with nucleosynthesispredictions. The new study features a line-by-line differential abundancecomparison of HD 115444 with the bright, well-studied halo giant HD 122563. ForHD 115444, the overall metallicity is [Fe/H]~ -3.0. The abundances of the lightand iron-peak elements generally show the same pattern as other UMP stars (e.g.overdeficiencies of manganese and chromium, overabundances of cobalt), but thedifferential analysis indicates several nucleosynthesis signatures that areunique to each star.Comment: To Appear in the Astrophysical Journa
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