2004/01/30 by Jennifer A. Johnson, Michael Bolte
Physics and Astronomy · #Astronomy and Astrophysical Research #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/382147
published as Astrophys.J. 605 (2004) 462 · to be published in ApJ
arxiv created 2004/01/30 · openalex publication_date 2004/04/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
The CH star CS 31062-050 ([Fe/H] = -2.42) is one of the most useful stars yet discovered for evaluating the s -process in metal-poor stars. It is very abundant in heavy elements (e.g., [La/Fe] = 2.2), and its relatively cool temperature and low gravity mean that there are many lines of interesting elements present in the spectrum. We measured the abundances of 22 elements with Z ≥ 29, including the rarely measured Lu and Pd. We derive an upper limit on the Th abundance as well. The abundances in CS 31062-050 show a similar pattern to many other metal-poor CH stars: high [Pb/Fe] and [Pb/La] ratios, low [Y/La] ratios and high [Eu/La] values compared to the solar system s -process. However, the Th limit, with additional assumptions, is not consistent with the idea that the excess Eu in CS 31062-050 is contributed by the r -process. In addition, the observed [Eu/Tb] cannot be explained by any ratio of solar-system s -process and r -process abundances. We therefore argue that the abundance pattern in CS 31062-050 is most likely the result of the s -process, and we discuss possible modifications that could explain the non-solar-system pattern observed.