Research Grants Program Office (RGPO)
Evidence of Multiple r-Process Sites in the Early Galaxy: New Observations of CS 22892-052.
- Author(s): Sneden, C
- Cowan, JJ
- Ivans, II
- Fuller, GM
- Burles, S
- Beers, TC
- Lawler, JE
- et al.
Published Web Locationhttps://doi.org/10.1086/312631
First results are reported of a new abundance study of neutron-capture elements in the ultra-metal-poor (&sqbl0;Fe&solm0;H&sqbr0;=-3.1) halo field giant star CS 22892-052. Using new high-resolution, high signal-to-noise ratio spectra, abundances of more than 30 neutron-capture elements (Z>30) have been determined. Six elements in the 40/=56) stable neutron-capture elements in CS 22892-052 match well the scaled solar system r-process abundance distribution. From the observed Th abundance, an average age of approximately 16+/-4 Gyr is derived for CS 22892-052, consistent with the lower age limit of approximately 11 Gyr derived from the upper limit on the U abundance. The concordance of scaled solar r-process and CS 22892-052 abundances breaks down for the lighter neutron-capture elements, supporting previous suggestions that different r-process production sites are responsible for lighter and heavier neutron-capture elements.