Nuclear Physics with Multi-Messenger Astronomy

The first detection in August 2017 of a binary neutron star merger in gravitational and electromagnetic waves marked the beginning of the era of multi-messenger astronomy. Future detections of neutron star-neutron star (NSNS) and neutron star-black hole (NSBH) mergers will allow astrophysicists to understand these systems in unprecedented detail, and test key theories about these exotic events. Two questions are especially interesting from a nuclear physics standpoint. First, what is the structure of ultra-dense neutron stars? Second, what is mergers' role in seeding the Universe with heavy elements synthesized via rapid neutron capture (the r-process)? I will discuss how observations of mergers can help us answer these questions. I will focus particularly on the radioactive transients that accompanies mergers (the so-called "kilonovae"), and explain how recent theoretical advances allow us to use kilonova observations to constrain open questions in nuclear astrophysics.