Site map . The explosion, which occurred some 10 billion years ago but only recently reached Earth, began as an intense burst of gamma-rays on Jan. 23. The blast had already faded to one four-millionth of its original brightness when Hubble snapped the above image in early February. The distant galaxy where the blast originated, located about two-thirds of the way to the edge of the observable universe, is not the classic spiral or elliptical shape. Scientists said it might be distorted by a collision with another galaxy, which would spur rapid star birth as gas clouds were heated and compressed.
Further evidence found in light patterns indicate the galaxy was full of newborn stars.
The new image lends support to the idea that such powerful explosions, which are not fully understood, seem to happen where vigorous star formation takes place. Tough to spot Scientists say gamma-ray bursts may be created by the mergers of a pair of neutron stars or black holes , or a hypernova, a theorized type of exceptionally violent exploding star. Though not all are as powerful as this one, gamma-ray bursts are known to occur at the rate of about one a day. Finding the explosions, however, has proved difficult. They occur without warning, of course, and they usually last for only a few seconds.