Cygnus X-1, the first black hole ever detected, is more massive than we thought

Seamless looping animation flying into the Nebula in Outer Space, also known as Cygnus Loop. 4K 3D rendering space exploration to the Nebula PIA15415 constellation Cygnus elements furnished by N

The discovery of black holes began as a theoretical curiosity following Einstein’s general relativity, but was confirmed in 1971 with Cygnus X-1, an invisible object pulling matter from a star.Black holes are regions where gravity is so intense that nothing, not even light, escapes the "event horizon." At their core lies a singularity of infinite density where known physics breaks down. They are often ringed by a glowing accretion disk of superheated gas, which allows astronomers to detect them.

Cygnus Constellation: Stars, Myth, and Location (2025) | Planet Guide