Type

Intermediate mass

Location

In the constellation Centaurus

Finder Chart

Distance

17,000 light-years

Mass

40,000 times the mass of the Sun

Size

Diameter 150,000 miles (240,000 km), about two-thirds of the distance from Earth to the Moon

Discovery Methods

• Measuring the motions of stars

Measuring the motions of stars

Because a black hole is both massive and compact, it exerts a strong gravitational pull on the material around it. Astronomers can deduce the presence of a supermassive black hole in the core of a galaxy by measuring the velocities of stars that orbit the black hole. A more-massive black hole will accelerate nearby stars to greater speeds, so the velocities of stars can reveal not only the presence of a black hole, but its mass as well.

More about black hole discovery methods »

This document was last modified: November 11, 2011.