Cygnus X-1
Cygnus X-1 is a stellar black hole in an X-ray binary in the constellation Cygnus, about 7,200 light-years (2.2 kpc) from Earth.
A black hole of about 21 solar masses pulling gas from a blue supergiant companion star. It was the subject of a famous 1974 bet between Stephen Hawking and Kip Thorne, and it launches small jets of its own.
Facts
| Type | Stellar black hole in an X-ray binary |
|---|---|
| Constellation | Cygnus |
| Position (J2000) | 19h 58m 21s, +35° 12′ |
| Distance | 7,200 light-years (2.2 kpc) |
When and how to see it
Cygnus X-1 is highest in the sky at midnight in July. From India (about 20° N) it climbs to about 75° above the horizon; from 50° N, to about 75°.
Heights are worked out for India and for 50° N. Set your location in Settings to see them for where you are.
For tonight's best time from your own town, the darkness and the Moon, open it on the map and see its "Tonight from your location" card.
More in Cygnus
- Cooling Tower Cluster (M29)
- Cygnus A
- Egg Nebula
- Fireworks Galaxy
- M39 (NGC 7092)
- North America Nebula
- Pelican Nebula
- Veil Nebula
Everything in Cygnus · All 88 constellations · All sky objects
Data: · Deep Sky Monitor's own notes · Data sources & credits