Swift’s UV Portrait of the Andromeda Galaxy

A patchy cool-blue ring of light surrounds the bright center of the M31 galaxy. The image is dotted with purple, blue and white stars.
NASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP)
CreditNASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP)
Historical DateSeptember 16, 2009
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NASA's Neil Gehrels Swift Observatory viewed our neighboring spiral galaxy Andromeda, also called M31, in ultraviolet light. The image was made from 330 images from Swift’s Ultraviolet/Optical Telescope. Some 20,000 ultraviolet sources are visible in the image, including M32, a small galaxy in orbit around M31. Dense clusters of hot, young, blue stars sparkle in the disk beyond the galaxy's smooth, redder central bulge.