Astronomy picture of the day 25-09-2014 - NGC 206 and the Star Clouds of Andromeda

NGC 206 and the Star Clouds of Andromeda
Image Credit and Copyright: Subaru Telescope (NAOJ),
Hubble Space Telescope,Local Group Galaxy Survey (Phil Massey, PI), Mayall 4-meter,Robert Gendler

Explanation: The large stellar association cataloged as

NGC 206 is nestled within the dusty arms of the neighboringAndromeda galaxy. Also known as M31,the spiral galaxy is a mere2.5 million light-years away. NGC 206 is near top center inthis gorgeous close-up of the southwesternextent of Andromeda's disk, a remarkable composite of data from space and ground-based observatories. The bright, bluestars of NGC 206 indicate its youth. In fact, its youngest massive stars are less than 10 million years old. Much larger than the open or galactic clusters of young starsin the disk of our Milky Way galaxy,NGC 206spans about 4,000 light-years. That's comparable in size to the giant stellar nurseriesNGC 604 in nearby spiralM33 and theTarantula Nebula, in the Large Magellanic Cloud. Star forming sites within Andromeda are revealed by the telltale reddish emission from clouds of ionized hydrogen gas.