Abstract

view Abstract Citations (456) References (98) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Ultra--Metal-poor, Neutron-Capture--rich Giant Star CS 22892-052 Sneden, Christopher ; McWilliam, Andrew ; Preston, George W. ; Cowan, John J. ; Burris, Debra L. ; Armosky, Bradley J. Abstract The K giant star CS 22892-052 is ultra-metal-poor ([Fe/H] ≃-3.1), but it has the largest abundance enhancements of neutron-capture elements yet discovered in any normal halo star. We have acquired new high-resolution, high signal-to-noise ratio spectra of CS 22892-052 and have determined a detailed abundance distribution of elements with Z > 30, in order to facilitate precise comparison with neutron-capture nucleosynthesis theories. Over 120 transitions throughout the wavelength range 3700- 6500 Å have been employed to derive abundances for 20 of these elements. We have detected several elements (Tb, Ho, Tm, Hf, and Os) never before seen in low-metallicity stars, and we have derived the abundance of Th from a clearly visible, mostly unblended, feature at 4019 Å. The elements from 56 ≤ Z ≤ 76 in CS 22892-052 are very well matched by a scaled solar system r-process abundance distribution. Scaled solar s-process or total abundances cannot be plausibly fitted to the observed data. The ratio of the Th abundance to that of any of these other elements is significantly subsolar, which suggests a much larger age for CS 22892-052 than 4.5 Gyr; a lower limit of 15.2±3.7 Gyr is inferred from a simple calculation. Publication: The Astrophysical Journal Pub Date: August 1996 DOI: 10.1086/177656 Bibcode: 1996ApJ...467..819S Keywords: NUCLEAR REACTIONS; NUCLEOSYNTHESIS; ABUNDANCES; STARS: INDIVIDUAL ALPHANUMERIC: CS 22892-052; STARS: POPULATION II full text sources ADS | data products SIMBAD (4)