Sunday, March 23, 2008

Gamma-Ray Burst Visible to Naked Eye

Scientists have found an interstellar explosion so bright that he briefly with the naked eye-from 7.5 billion light years away.

Viewers looking for the right patch of the night sky on Wednesday had seen several afterglows from the massive gamma-ray burst, somewhat brighter than the faintest stars visible.

NASA Swift satellite recorded the unprecedented spectacle with its X-Ray Telescope (left) and optical / UV telescope (right). The burst GRB 080319B was named because it was the second of four bursts detected that the first day for Swift.

GRB 080319B, is more than half in the entire visible universe, crushed the previous record holder for the most distant object visible without the help of three orders of magnitude. That would be the galaxy M33, only 2.9 million light years from Earth.

"That was a stunner burst," Swift Principal Investigator Neil Gehrels of NASA Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. "It blows away every gamma-ray burst so far we have seen."

Gamma-ray bursts occur when massive stars run out of fuel and collapse, casting, fast huge quantities of radiation and high energy particles. Acting as high-power cosmic blowtorches, particle jets can also heat interstellar clouds to create bright afterglows, according to scientists.

The bursts are the most brilliant occurrences in the universe after the Big Bang. GRB 080319B the afterglows, for example, seemed to 2.5 million times stronger than the brightest supernova on record.

Researchers are still unsure why GRB 080319B was so bright. Some theories originating a star with an unusual mass, spin, or magnetic field or a particularly concentrated energy jet.