Masses in the stellar graveyard (IMAGE) CNRS Caption The masses of neutron stars and black holes measured through gravitational waves (blue and orange) and electromagnetic observations (yellow and purple). GW 200105 and GW 200115 are highlighted as the merger of neutron stars with black holes. Credit © LIGO-Virgo / Frank Elavsky, Aaron Geller / Northwestern Usage Restrictions May only be used to report on this work, with appropriate credit and caption. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.