Gamma Ray Burst Afterglow: Supernova Connection . ... XMM Result: J.N. Reeves, D. Watson, J.P. Osborne ( University of Leicester ), et al. Explanation: What causes the mysterious gamma-ray bursts ? ... The exciting result is evidence that the gamma-ray burst itself is linked to a very energetic supernova explosion which may have preceded the powerful flash of gamma-rays by up to a few days. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...