We present detailed chemical abundances of three new bright ( V \sim 11 ) , extremely metal-poor ( [ Fe/H ] \sim - 3.0 ) , r -process-enhanced halo red giants based on high-resolution , high- S / N Magellan/MIKE spectra .
We measured abundances for 20-25 neutron-capture elements in each of our stars .
J1432 - 4125 is among the most r -process rich r -II stars , with [ Eu/Fe ] = +1.44 \pm 0.11 .
J2005 - 3057 is an r -I star with [ Eu/Fe ] = +0.94 \pm 0.07 .
J0858 - 0809 has [ Eu/Fe ] = +0.23 \pm 0.05 and exhibits a carbon abundance corrected for evolutionary status of \mbox { [ C / Fe ] } _ { corr } = +0.76 , thus adding to the small number of known carbon-enhanced r -process stars .
All three stars show remarkable agreement with the scaled solar r -process pattern for elements above Ba , consistent with enrichment of the birth gas cloud by a neutron star merger .
The abundances for Sr , Y , and Zr , however , deviate from the scaled solar pattern .
This indicates that more than one distinct r -process site might be responsible for the observed neutron-capture element abundance pattern .
Thorium was detected in J1432 - 4125 and J2005 - 3057 .
Age estimates for J1432 - 4125 and J2005 - 3057 were adopted from one of two sets of initial production ratios each by assuming the stars are old .
This yielded individual ages of 12 \pm 6 Gyr and 10 \pm 6 Gyr , respectively .