Gamma ray burster GRB 110328A as imaged by the SWIFT spacecraft. GRB's occur suddenly and briefly, often in places of the sky where nothing was seen before. SWIFT was specifically designed to catch GRB's on the fly, focusing on them immediately after they occur. Curiously, this GRB, which was first seen March 28, has lasted for days. Gamma radiation has repeatedly flared then faded. Space.com article Scientists are not sure why this gamma ray burst is so long-lasting. They think that its power source must be a massive Black Hole.