Cygnus X-1’s black hole was first discovered more than half a century ago. But it continues to teach us new things. ... The team plans to follow up with more observations of Cygnus X-1.

In 1974 Stephen Hawking and Kip Thorne placed a bet on whether Cygnus X-1 was really a black hole. The wager was settled in 1990, but the world’s first black hole is still a mystery.

IXPE observed Cygnus X-1, which is an X-ray binary system consisting of a 21-solar-mass black hole and a 41-solar-mass companion star 7,200 light years away in the constellation of Cygnus the Swan ...

An artist’s impression of the Cygnus X-1 system. A stellar-mass black hole orbits with a companion star located 7,200 light years from Earth.

AT 2021hdr occurs in a galaxy located a billion light-years away in the constellation Cygnus. The two black holes are separated by 26 billion kilometers, close enough for light to take just one ...

To strive for the most complete understanding of a black hole, astronomers have turned their telescopes to the double-star system Cygnus X-1, which boasts the first of these discovered oddities.

WHAT’S NEW — In 1971, Cygnus X-1 became the first black hole to be observed from Earth. While black holes had long been predicted theoretically, Cygnus X-1 became the first to be positively ...

V404 Cygnus is some 8,000 light years from Earth and has been long known to be in process of eating a star orbiting very tightly around it, whipping around the black hole once every 6.5 days.

The Cygnus X-1 system is one of the brightest sources of X-rays in the Milky Way, consisting of a black hole called Cygnus X-1 and its giant companion, a star packing 41 times the mass of our Sun ...

A tiny fraction of known black holes emit X-ray signals that resemble a human "heartbeat." Now, new research may finally explain the strange phenomenon.

To strive for the most complete understanding of a black hole, astronomers have turned their telescopes to the double-star system Cygnus X-1, which boasts the first of these discovered oddities.