1997/04/22 by S. Castro, R. M. Rich, R. Michael Rich +4 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/118481
19 pages (Latex), 4 Tables (Latex), 11 postscript figures. Tables 2a and 2b are available upon request. Accepted for publication in The Astronomical Journal
arxiv created 1997/04/22 · openalex publication_date 1997/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report detailed analysis of high-resolution spectra of nine high velocity metal-rich dwarfs in the solar neighborhood, selected from the proper motion samples of Grenon. The stars are super metal-rich, and 5 of them have fe >= +0.4, making them the most metal-rich stars currently known. We find that alpha -elements decrease with increasing metallicity; s-elements are underabundant by about [s-elements/Fe] ~ -0.3; the ionEu2 line was measurable for 6 stars, showing [Eu/Fe] ~ 0.0, except for G161-29 where [Eu/Fe] = +0.50. All calculations followed the same methods used by Castro et al. (1996) [AJ, 111, 2439] for the analysis of the well-known metal-rich prototype mul and the very strong-lined bulge star bww, for which fe =+0.46 and +0.47 were found respectively. While exceeding the [Fe/H] of current bulge samples, the chemistry of these stars has important similarities and differences. The near-solar abundances of the alpha-capture elements places these stars on the metal-rich extension of McWilliam & Rich (1994) [ApJS, 91, 749], but their s-process abundances are much lower than those of the bulge giants. These low s-process values have been interpreted as the hallmark of an ancient stellar population. We are unable to convincingly assign these stars to a known Galactic population and we urge further studies of larger samples.