Swift's UV Portrait of the Andromeda Galaxy
Credit: NASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP)
Published: September 16, 2009
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.
More information: https://svs.gsfc.nasa.gov/10485