First results are reported of a new abundance study of neutron-capture elements in the ultra-metal-poor ( UMP ; [ Fe/H ] = –3.1 ) halo field giant star CS 22892-052 .
Using new high resolution , high signal-to-noise spectra , abundances of more than 30 neutron-capture elements ( Z > 30 ) have been determined .
Six elements in the 40 < Z < 56 domain ( Nb , Ru , Rh , Pd , Ag and Cd ) have been detected for the first time in a UMP star .
Abundances are also derived for three of the heaviest stable elements ( Os , Ir , and Pb ) .
A second transition of thorium , \ion Th2 \lambda 4086 Å , confirms the abundance deduced from the standard \ion Th2 \lambda 4019 Å line , and an upper limit to the abundance of uranium is established from the absence of the \ion U2 \lambda 3859 Å line .
As found in previous studies , the abundances of the heavier ( Z \geq 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 \simeq 16 \pm 4 Gyr is derived for CS 22892-052 , consistent with the lower age limit of \simeq 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 .