Alternate Names

NGC 4649, Arp 116

Type

Supermassive

Location

In the constellation Virgo

Finder Chart

Distance

51 million light-years (15.6 megaparsecs)

Mass

4.5 billion times the mass of the Sun

Size

Diameter 45 billion miles (27 billion km), roughly eight times the diameter of Neptune's orbit around the Sun

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: March 14, 2012.