GW170817
Gravitational-wave signal detected in 2017
GW170817 was a gravitational wave (GW) observed by the LIGO and Virgo detectors on 17 August 2017, originating within the shell elliptical galaxy NGC 4993, about 140 million light years away. The wave was produced by the last moments of the inspiral of a binary pair of neutron stars, ending with their merger. As of December 2025, it is the only...
