Type

Stellar mass

Location

in the constellation Cassiopeia

Distance

2.4 million light-years (740 kiloparsecs)

Mass

23 times the mass of the Sun

Size

Diameter roughly 80 miles (140 km), about the size of Connecticut

Discovery Methods

• Detection of an accretion disk
• Measuring the motions of a companion star

IC 10, the black hole's host galaxy, is a small puff of stars more than two million light-years away. [Adam Block/NOAO/AURA/NSF]

This document was last modified: May 31, 2011.