GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

Understand

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes.

• The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC.
• The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences.
• Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5 $\sigma$.