Key facts
- Category
- Black holes
- Object class
- Stellar black hole
- Mass
- ~21 solar masses
- Scale fact
- 120 kmevent horizon diameter
- Estimated age
- ~5 million years
- Host
- Cygnus X-1 binary system
Cygnus X-1
120 kmevent horizon diameter
Visual creditscaleofspace.org / CC BY-NC 4.0
Details
Cygnus X-1 was the first cosmic object widely accepted as a black hole. It blazes in X-rays because the black hole is stripping hot gas from a massive blue supergiant companion and funneling it into a compact accretion flow.
Cygnus X-1 contains a black hole with a measured mass of about 21 solar masses, orbiting a massive blue supergiant. Gas drawn from the star heats in an accretion flow and emits X-rays; the black hole itself remains unseen.
The system became the first widely accepted stellar-mass black hole because its compact object was too massive to be a neutron star. Radio astrometry and optical measurements have since refined both its distance and mass.
Links
- Editorial guides
- Universe journey
- Milky Way
- Preset views
- Wikipedia
- Cygnus X-1 on Wikipedia
Size neighbors
Objects near Cygnus X-1 on the scale
On the logarithmic size axis, Cygnus X-1 falls between Pandora and 21 Lutetia. The band uses nearby Black holes records.
Shared physical scale
181billion km
Sources
References for Cygnus X-1
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Cygnus X-1 — Wikipedia
- Visual: scaleofspace.org / CC BY-NC 4.0
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About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.