V404 Cygni
Stellar-mass black hole
A black hole that flares to life every few decades, briefly becoming one of the brightest X-ray sources in the sky.
Computed render9.0 ☉
mass (the Sun = 1)
27 km
event-horizon radius (computed)
7,800 ly
from Earth
Mass is a best estimate from the cited observations, which carry their own measurement uncertainty.
Its event horizon, the edge past which nothing returns, spans about 27 km in radius.
It lives in
Milky Way
Barred spiral galaxy.
Black holes of similar mass
LMC X-1Stellar-mass10.9 ☉GW200115_042309Gravitational-wave source7.2 ☉GW190917_114630Gravitational-wave source11.6 ☉GW241109_115924Gravitational-wave source11.9 ☉A0620-00Stellar-mass6.6 ☉GRS 1915+105Stellar-mass12.4 ☉
Worlds in the same direction on the sky→