Brightest Gamma-Ray Burst Ever
NASA astronomers were blown away last week by what was far and away the strongest gamma-ray burst (GRB) ever observed. GRB 080319B, shown here in x-ray [left] and optical/ultraviolet [right] views captured by the Swift satellite, burned so brightly that its afterglow was briefly visible to the naked eye from its origin 7.5 billion light-years (or half a universe) away. If placed side-by-side with the brightest supernova ever seen, the burst would still outshine it by a factor of 2.5 million, researchers calculated. GRBs typically occur when the explosion of a dying star gets channeled into twin high-speed jets. Astronomers are mystified why this one shined so intensely. The burst may simply have been extra powerful or its very narrow jets may have pointed directly at Earth.