The High Energy Transient Explorer detected the 2.5 second gamma-ray burst and relayed its location to telescopes worldwide in 22 seconds. The RAPTOR ground-based telescope caught the afterglow 65 seconds later, on the edge of a galaxy several billion light years away. Here we see the afterglow fading fast at about 65 seconds (left image), then 9 minutes (right). The afterglow was undetectable about two hours later. CREDIT: P. Wozniak, W.T. Vestrand, et al., RAPTOR Project, LANL
