On 17 August 2017, Fermi Gamma-Ray Burst Monitor software detected, classified, and localized a gamma-ray burst which was later designated as GRB 170817A. Six minutes later, a single detector at Hanford LIGO registered a gravitational-wave candidate which was consistent with a binary neutron star merger, occurring 2 seconds before the GRB 170817A event. This observation was "the first joint detection of gravitational and electromagnetic radiation from a single source ".