Geocheminar Winter-2018

It has long been realized that approximately half of the elements heavier than iron are formed via a process known as rapid-neutron capture (r-process) nucleosynthesis. However, it has been less clear where the r-process predominantly occurs, with proposed sites including core-collapse supernovae and neutron star mergers. In this talk I will give a broad overview of our current understanding of the origin of r-process elements, with an emphasis on results from the recent discovery of an electromagnetic counterpart to the neutron star merger GW170817. I will review our previous constraints on the origin of the r-process elements from both theory and observations of metal-poor stars. I will then describe the optical and infrared emission associated with the the binary neutron star merger, GW170817, and place these new results in context. I will discuss the implications of these observations on our understanding of the ejecta from neutron star mergers, the synthesis of r-process elements, and the enrichment of the interstellar medium with this material.