Astronomers have detected the most distant gamma-ray burst ever found. The cosmic explosion came from a star that detonated about 12.8 billion light years from Earth.
Gamma-ray bursts are fleeting blasts of high-energy radiation that occur when massive stars die and shoot out high-speed jets of matter. The expanding matter initially produces gamma rays, but when it starts colliding with surrounding gas, it creates afterglows at longer wavelengths.
The new record holder, called GRB 080913, was first detected on 13 September by NASA’s Swift space observatory. Telescopes around the world soon detected its afterglow at longer wavelengths, and the light spectrum they observed revealed its incredible distance: 12.8 billion light years away.
That is about 70 million light years farther than the previous record holder. “This is the most amazing burst Swift has seen,” said Swift’s lead scientist Neil Gehrels in a statement.
Astronomers have been hoping to discover very distant GRBs because they exploded when the universe was young – they are being seen now because their light took billions of years to reach Earth. These ancient GRBs could reveal details about the lives and deaths of the very earliest stars.
GRB 080913 exploded less than 825 million years after the big bang. “This burst accompanies the death of a star from one of the universe’s early generations,” said Swift team member Patricia Schady of University College London.
Taken from NewScientist