After detecting two gravitational-wave signals in September and December of 2015, the LIGO (Laser Interferometer Gravitational-Wave Observatory) Scientific and Virgo Collaborations are now reporting their third catch. On 4 January 2017, the LIGO instruments recorded a gravitational-wave “chirp” from the merger of two black holes whose combined mass is 50 times that of the Sun.
Link: https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.118.221101
