### Another bit of gravity

After the first detection of gravitational waves from merged black holes, LIGO detected a new signal:
The two LIGO gravitational wave detectors in Hanford Washington and Livingston Louisiana have caught a second robust signal from two black holes in their final orbits and then their coalescence into a single black hole. This event, dubbed GW151226, was seen on December 26th at 03:38:53 (in Universal Coordinated Time, also known as Greenwich Mean Time), near the end of LIGO's first observing period ("O1"), and was immediately nicknamed "the Boxing Day event".