We report an abundance analysis for the highly r -process-enhanced ( r -II ) star CS~29497-004 , a very metal-poor giant with T _ { \mathrm { eff } } = 5013 K and [ Fe/H ] = -2.85 , whose nature was initially discovered in the course of the HERES project .
Our analysis is based on high signal-to-noise , high-resolution ( R \sim 75000 ) VLT/UVES spectra and MARCS model atmospheres under the assumption of local thermodynamic equilibrium , and obtains abundance measurements for a total of 46 elements , 31 of which are neutron-capture elements .
As is the case for the other \sim 25 r -II stars currently known , the heavy-element abundance pattern of CS~29497-004 well-matches a scaled Solar System second peak r -process-element abundance pattern .
We confirm our previous detection of Th , and demonstrate that this star does not exhibit an “ actinide boost ” .
Uranium is also detected ( \log \epsilon ( \mathrm { U } ) = -2.20 \pm 0.30 ) , albeit with a large measurement error that hampers its use as a precision cosmo-chronometer .
Combining the various elemental chronometer pairs that are available for this star , we derive a mean age of 12.2 \pm 3.7 Gyr using the theoretical production ratios from waiting-point approximation models ( Kratz et al .
2007 ) .
We further explore the high-entropy wind model ( Farouqi et al .
2010 ) production ratios arising from different neutron richness of the ejecta ( Y _ { e } ) , and derive an age of 13.7 \pm 4.4 Gyr for a best-fitting Y _ { e } = 0.447 .
The U/Th nuclei-chronometer is confirmed to be the most resilient to theoretical production ratios and yields an age of 16.5 \pm 6.6 Gyr .
Lead ( Pb ) is also tentatively detected in CS~29497-004 , at a level compatible with a scaled Solar r - process , or with the theoretical expectations for a pure r -process in this star .