Photos of the Day 23.11.2013
This photo shows a gamma-ray burst traveling at nearly the speed of light. Gamma-ray bursts are the most powerful explosions in the universe and occur in supernova or hypernova explosions of very massive stars.
AM 0644-741, located 300 million light-years away from us, is a ring galaxy. Such galaxies typically obtain their rings from collisions with another galaxy. It is 150,000 light-years across, half the size of the Milky Way.