The fourth gravitational wave signal detected by LIGO GW170817 coincided with a short gamma ray burst and these signals have been interpreted as the result of a binary neutron star merger. It is thought that gold and other heavy elements are produced in binary neutron star collisions and the GW170817 event has provided support for this idea. Further evidence that heavy elements are produced in extremely rare events such as binary neutron star mergers has been deduced from the scarcity of these elements in dwarf galaxies. The Reticulum II dwarf galaxy is an exceptional case that does contain heavy elements that might have been created in a single such event.
The gravitational-wave signal generated by a galactic population of double neutron-star binaries
