GW170809
Gravitational-wave source · GWTC-2.1-confident
A black hole of about 56 solar masses, formed on 2017-08-09 when two black holes of roughly 34 and 24 solar masses spiralled together 3.5 billion light-years away. LIGO and Virgo felt the collision as ripples in spacetime.
Computed render55.7 ☉
mass (the Sun = 1)
165 km
event-horizon radius (computed)
3.5 billion ly
from Earth
34+24 ☉
the two that merged
The two black holes that merged were about 34 (29–42) and 24 (19–29) solar masses. The remnant is 56 (52–61) solar masses. Values in parentheses are the 90% credible ranges from LIGO, Virgo and KAGRA (GWTC).
Its event horizon, the edge past which nothing returns, spans about 165 km in radius. The waves we detected had been travelling for 3.5 billion years before they reached us.
Black holes of similar mass
GW240930_234614Gravitational-wave source55.5 ☉GW200302_015811Gravitational-wave source55.5 ☉GW190527_092055Gravitational-wave source55.5 ☉GW190413_052954Gravitational-wave source55.5 ☉GW241009_220455Gravitational-wave source56.0 ☉GW240420_175625Gravitational-wave source56.0 ☉
Source: Gravitational-Wave Open Science Center (GWTC-2.1-confident), LIGO Virgo KAGRA. CC BY 4.0. See data & analysis for full sourcing.