spacetoday.net: Spacecraft detects distant GRB

Posted: Tue, Sep 13, 2005, 6:37 AM ET (1037 GMT)
Swift spacecraft illustration (NASA)

A NASA spacecraft has observed what astronomers believe to be the most distant gamma-ray burst (GRB) ever, a blast that dates back to the early history of the universe. The Swift spacecraft detected the burst, designated GRB 050904, on September 4, and astronomers calculated that the burst had a redshift of 6.29. That corresponds to a distance of about 13 billion light-years, implying that the burst dates back to about 500 million to 1 billion years after the Big Bang. Only one object, a quasar, has been found at a greater distance than this GRB. The burst appears to have been caused by a single star, but astronomers are puzzled how a star could generate a burst that powerful.