Shivani Shah (U. Florida)

Several aspects of the r-process remain unclear, including its primary astrophysical site(s), properties of its enrichment events (e.g., occurrence rate), and resulting yields of elements. Metal-poor, r-process enhanced stars offer a unique probe of these aspects, since they carry chemical signatures from only a few progenitor r-process enrichment events. In this talk, I will describe (1) the determination of robust stellar ages (independent of stellar evolution models) with a novel set of uranium absorption lines, (2) constraints on the yields of rarely examined elements (e.g., cadmium and gold) via UV and optical spectroscopy, and (3) the distribution of actinide mass fraction in metal-poor stars with the largest sample of thorium abundances to date. I will further discuss how these results, in tandem with the much anticipated JWST observations of r-process signatures in kilonovae, can be used to constrain the primary astrophysical site(s) of the r-process.