These images, taken with NASA's Galaxy Evolution Explorer (GALEX) and the Pan-STARRS1 telescope in Hawaii, show a galaxy that brightened suddenly, caused by a flare from its nucleus. The flare is a signature of the galaxy's central black hole shredding a star that wandered too close. The top left image, taken by GALEX in 2009, shows the galaxy before the flare, when it wasn't visible in ultraviolet light. In the top right image, taken by GALEX on June 23, 2010, the galaxy had become 350 times brighter in ultraviolet light. The bottom left image, taken by Pan-STARRS1, shows the galaxy (the bright dot in the center) in 2009 before the flare's appearance. The bottom right image, taken by Pan-STARRS1 from June to August 2010, shows the flare from the galaxy nucleus. Note how the light from the flare is much bluer (hotter) than the host galaxy light.
Credit: NASA/S. Gezari (JHU)/A. Rest (STScI)/R. Chornock (Harvard-Smithsonian CfA)