Alternate Names

NGC 224

Type

Supermassive

Location

in the constellation Andromeda

Finder Chart

Distance

2.5 million light-years (0.78 megaparsecs)

Mass

30 million times the mass of the Sun

Size

Diameter roughly equal to the orbit of Venus.

Discovery Methods

• Measuring the motions of stars

M31

A close-up view of the disk of M31. Bright young stars outline the spiral arms, which are intertwined with dark lanes of dust that absorb light from the stars behind them.

A Hubble Space Telescope image of M31's "˜double nucleus."™ The two bright blobs of stars may encircle a supermassive black hole.

X-ray images show the center of the Andromeda galaxy before (left) and after a flare-up in early 2006. The black hole is inside the top blob.

This image shows the entire Andromeda Galaxy at right, with a close-up of its nucleus from the orbiting Chandra X-Ray Observatory. The Chandra image shows sources that are very hot. The large yellow over just above the bright blue spot at the center of the Chandra image represents a disk of hot gas surrounding the black hole.

Mysterious disk of blue stars around M31's black hole

This document was last modified: April 30, 2012.