NASA’s Swift spacecraft has detected a gamma-ray burst, called GRB 111209A, which is one of the longest events of this kind ever observed. The duration of gamma-ray emission from GRB 111209A was approximately 2 hours. Swift X-Ray Telescope image of GRB 111209A (Swift team) An international team of astronomers using the Burst Alert Telescope on-board Swift spacecraft recorded this unusual event on December 9, 2011. Follow-up observations, started...
