Last updated on April 18, 2014 at 21:21 EDT
Messier 101 - Ultraviolet and Visible
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Messier 101 - Ultraviolet and Visible

April 18, 2005
This is a three color image of the nearby spiral galaxy Messier 101 (M101). It is a combination of GALEX images taken with the FUV and NUV detectors, (colored blue) and two images in visible light from the Digital Sky Survey (colored green and orange). The UV light observed by GALEX is concentrated in the spiral arms of this galaxy and shows the presence of young stars (only 10 million years old). The more diffuse green visible light traces stars that have been living for more than 100 million years. The red visible light image shows the stars that formed over a billion years ago.

This image traces the evolution of star formation in M101 and shows the impact GALEX observations will have on the study of galaxy formation and evolution.