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Black Holes Encyclopedia

Alternate Names

Cygnus XR-1


Stellar mass


In the constellation Cygnus

Finder Chart


6,000 to 10,000 light-years


15 times the mass of the Sun


Diameter 55 miles (90 km), equal to the size of a large American city

Discovery Methods


Cygnus X-1

Imagining Cygnus X-1

An artist's concept of Cygnus X-1 shows hot gas from the giant blue star flowing toward the black hole, forming a bright accretion disk.

Cygnus X-1

This gamma-ray image from the Integral satellite shows Cygnus X-1 (the large white blob at center) and Cygnus X-3, which is an accretion disk encircling a neutron star.

Cygnus X-1

A view of the region around Cygnus X-1, with the system outlined by the red box.


X-ray image of Cygnus X-1.

Spinning and Non-Spinning Black Holes

Data from orbiting X-ray observatories show how the gravitational field of the Cygnus X-1 black hole accelerates gas around it.

This document was last modified: April 29, 2013.