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.

January 22, 1999
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Pegasus dSph: Little Galaxy of the Local Group
Credit: E. Grebel (U. Washington), P. Guhathakurta (UCO/Lick)

Explanation: The Pegasus dwarf spheroidal galaxy (Peg dSph) is a small, newly recognized member of the Local Group of Galaxies. Likely a satellite companion of the Local Group's dominant player, the large spiral Andromeda (M31), the Pegasus dwarf galaxy is almost hidden in the glare of relatively bright foreground stars in our own Milkyway. Still, this dramatic Keck telescope 3-color image reveals Peg dSph as a clump of fainter, bluer stars 2,000 or so light-years across. Excitement over discoveries of Peg dSph and other nearby dwarf galaxies reflects the fact that little galaxies may loom large in the process of galaxy evolution. They are thought to be the building blocks from which larger galaxies are constructed.

Tomorrow's picture: Saturnian Saturday

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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.