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Black Holes Encyclopedia
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Alternate Names

Sagittarius A*

Type

Supermassive

Location

In the constellation Sagittarius

Finder Chart

Distance

27,000 light-years (8 kiloparsecs)

Mass

4.1 million times the mass of the Sun

Size

Diameter roughly 15 million miles (24 million km).

Discovery Methods

Images

Milky Way

Center of Milky Way Sagittarius A*

A view of the center of the Milky Way from a ground-based telescope, with arrows pinpointing the location of Sgr A*.


Radio Image of Sgr A*

A radio image of the center of the galaxy shows Sgr A* as a white dot at center, surrounded by clouds of gas.


Hiding a Black Hole

The supermassive black hole at the center of our Milky Way galaxy lies behind dense clouds of gas and dust. The center of the galaxy is a little above the "spout" of the teapot-shaped constellation Sagittarius at the upper right of this photograph. It's about 27,000 light-years away. Recent observations show that the black hole occasionally produces flares of energy, perhaps caused by its complex magnetic field.


Center of the Milky Way

An infrared view of the central region of the Milky Way galaxy shows several massive stars that orbit the galaxy's supermassive black hole.


Milky Way Sagittarius A*

A look at the core of the Milky Way from the orbiting Chandra X-Ray Observatory. The black hole is near the center of the image, which shows hot stars and large clouds of hot gas.


Glowing Heart

This 2005 infrared view from Spitzer Space Telescope captures the heart of the Milky Way in stunning detail. The red filaments are glowing clouds of gas and dust, while the brighter knots of material are nurseries for new star birth. Sagittarius A* is at the middle of the large, bright concentration at the center of the image.


Sagittarius A*

Gas and dust spirals toward the black hole at the center of the Milky Way in this composite visible and infrared image from two space telescopes. The disk is several light-years wide, and may be giving birth to new stars in its outer regions.


Motions of Stars Around Sgr A*

This diagram shows the motions of several stars around Sgr A*.


Flares from the Center of the Milky Way

Flares from the accretion disk around the black hole at the center of the galaxy.


This document was last modified: February 12, 2012.