GW150914

two black holes merging · the first gravitational waves detected

1.3 billion light-years from Earth

1.3 billion years ago two black holes of 36 and 29 Suns spiralled together and merged. They gave off no light, but three Suns' worth of energy left as ripples in spacetime, which reached detectors on Earth on 14 September 2015.

• wave frequency 35 Hz and rising: the "chirp"
• the pair is circling 18 times a second (shown slowed down)

kind

black hole · explosion or collision