Presentation #343.07 in the session “Milky Way & Galactic Center”.
The chemical composition of a star can give insight about its origin. Moreover, the abundance patterns of stars can give us clues into their chemical enrichment and formation history. In this poster, we will explore the chemical elements produced by the rapid neutron capture process, commonly known as the r-process. This is the process by which the elements heavier than strontium in the periodic table are created, such as thorium and europium. We present the detailed chemical abundance pattern of the metal poor ([Fe/H]= -2.22), highly enhanced r-process star, J1453+0040. Discovered as part of the R-process Alliance collaboration, this star is one of the most highly enhanced r-process stars, with [Eu/Fe]=+1.90 and log ε(Eu)=+0.03. We also detected thorium, with [Th/Fe]=+1.60. Such high enhancements of r-process elements as found in J1453+0040 are very interesting as they can provide constraints on the yields and astro-physical sites of the r-process, including likely contenders such as neutron star mergers or magneto-rotational supernovae. From these detailed abundance patterns, we can infer the properties of neutron star mergers, including their mass ratios, energies, and spins. Furthermore, highly enhanced r-process stars, like J1453+0040, allow us to gain insight into the properties of phenomena like the kilonova detected by the electromagnetic counterpart of LIGO, particularly its blue and red components.