Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2001 September 17
See Explanation. Clicking on the picture will download the largest version available.

Southwest Andromeda
Credit & Copyright: Satoshi Miyazaki (NAOJ) et al., Suprime-Cam, Subaru Telescope, NOAJ

Explanation: This new image composite of the southwest region of M31 from the Subaru Telescope shows many stars, nebulae, and star clusters never before resolved. An older population of stars near Andromeda's center causes the yellow hue visible on the upper right. Young blue stars stand out in the spiral arms on the lower left. Red emission nebula, blue open clusters of stars, and sweeping lanes of dark dust punctuate the swirling giant. Andromeda, at about 2.5 million light years distant, and our Milky Way are the largest galaxies in the Local Group of Galaxies. Understanding M31 helps astronomers to understand our own Milky Way Galaxy, since the two are so similar.

Tomorrow's picture: Surrounded by Mars

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.