Kilonova
A kilonova (also called a ‘macronova’ or an ‘r-process supernova’) occurs when two neutron stars or a neutron star and a black hole merge. Strong electromagnetic radiation is emitted due to the decay of heavy r-process ions that are produced and ejected fairly isotropically during the merger process—similar to a faint, short-lived supernova.
A kilonova is thought to be the result of merging of two compact objects, namely a black hole and neutron star, in a binary system. The inspiral and merging of these compact objects are thought to be a strong source of gravitational waves (GWs). It is also thought to be the progenitor of short gamma-ray bursts and the predominant source of stable r-process elements in the Universe.