Today (February 11, 2016), Laser Interferometer Gravitational-Wave Observatory (LIGO) announced the first-ever detection of gravitational waves [1], opening a new era in Astronomy.
The signal recorded by LIGO on September 14, 2015, is consistent with a black-hole merger of 36 and 29 solar masses – resulting in a black hole of 62 solar masses. The remaining 3 solar masses “was converted into gravitational waves in a fraction of a second — with a peak power output about 50 times that of the whole visible universe” [2].
[1] LIGO detection announcement (https://www.ligo.caltech.edu/detection)
[2] LIGO press-release (http://ligo.org/news/detection-press-release.pdf)