AAS Meeting #193 - Austin, Texas, January 1999
Session 45. Spectral Observations of Stars
Display, Thursday, January 7, 1999, 9:20am-6:30pm, Exhibits Hall 1

## [45.12] A New Exploration of the Spectrum of CS 22892-052

C. Sneden (U. Texas), G.M. Fuller (UCSD), S. Burles (U. Chicago), T.C. Beers (Michigan State U.), J.J. Cowan (U. Oklahoma)

New high resolution, high signal-to-noise spectra of the ultra-metal-poor, neutron-capture-rich halo giant CS~22892-052 have been obtained with the Keck~I 10m and McDonald 2.7m telescopes. The Keck spectra cover the near-UV spectral region (3100--4300Å) and the McDonald spectra are most useful in the yellow-red region (5000--9000Å). We have analyzed many new near-UV lines of previously studied neutron-capture elements (such as Y, Zr, Nd, and Dy) in CS~22892-052. These new transitions are used to increase the reliability of the abundances of those elements and to show that abundances deduced from near-UV features are the same as those from the visible spectral region. More importantly, with the new spectra we have identified transitions of several previously undetected neutron-capture elements in the range 41\leqZ\leq48 (especially Pd, Ag, and Cd), and elements of the third neutron-capture peak (Os, Ir, and Pt). We also detect, for the first time in metal-poor stars, a second line of Th~II at 4086Å. The Th abundance deduced from this line is consistent with that obtained from the standard'' 4019Å\ Th~II line, increasing the confidence in the use of the Th as a cosmochronometer.