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R-process pattern in the Very-Metal-Poor Halo Star CS31082-001

Astrophysics 2007-05-23 v1

Abstract

The very-metal-poor halo star CS31082-001 was discovered to be very strongly r-process-enhanced during the course of a VLT+UVES high-resolution follow-up of metal-poor stars identified in the HK survey of Beers and colleagues. Both the strong n-capture element enhancement and the low carbon and nitrogen content of the star (reducing the CN molecular band contamination) led to the first 238^{238}U abundance measurement in a stellar spectrum (Cayrel et al. 2001), and the opportunity to use both radioactive species 238^{238}U and 232^{232}Th for dating the progenitor to this star. However, age computations all rely on the hypothesis that the r-process pattern is solar, as this was indeed observed in the other famous r-process-enhanced very metal poor stars CS22892-052 (Sneden et al. 1996, 2000) and in HD115444 (Westin et al. 2000). Here, we investigate whether this hypothesis is verified also for CS31082-001, using a preliminary analysis of over 20 abundances of n-capture elements in the range Z=38 to Z=92.

Keywords

Cite

@article{arxiv.astro-ph/0104172,
  title  = {R-process pattern in the Very-Metal-Poor Halo Star CS31082-001},
  author = {V. Hill and B. Plez and R. Cayrel and T. C. Beers},
  journal= {arXiv preprint arXiv:astro-ph/0104172},
  year   = {2007}
}

Comments

3 pages, 2 figures. To appear in `Astrophysical Ages and Timescales' ASP Conf. Ser., Eds. T. von Hippel, N. Manset, C. Simpson