Astronomy Picture of the Day

Explanation: Modern astronomers keep a long list of things that go bump in the night. Near the top are supernovae - the death explosions of massive stars, and gamma-ray bursts - the most powerful explosions seen across the Universe. Intriguingly, the galaxy seen above in a Hubble Space Telescope image may have been host to both a supernova and a gamma-ray burst which were one and the same event. ESO 184-G82 is a spiral galaxy with a prominent central bar and loose spiral arms dotted with bright star-forming regions. The inset shows an expanded view of one of the star-forming regions, about 300 light-years across, indicating the location of an extraordinarily powerful supernova estimated to have exploded on April 25, 1998. That location and date also correspond to an unusual gamma-ray burst, which may be representative of a peculiar class of these cosmic high-energy flashes. But so far, this combination is unique and makes barred spiral ESO 184-G82, at a distance of only 100 million light-years, the closest known gamma-ray burst host galaxy.