Left, "before" image, from the Sloan Digital Sky Survey. Right, "after" image, from Swift's Ultraviolet/Optical Telescope. The pinpoint of light in the centre is the GRB, which outshines the entire host galaxy. Click image for the high resolution image [8.7MB tiff].
NASA's Swift telescope has detected a gamma-ray burst (GRB), a usual harbinger of a supernova, very close to our galaxy, in the constellation Aries. The GRB was detected on Feb. 18th, at 440 million light-years away, lasting 33-minutes -- quite the departure for GRBs, which are usually detected billions of light-years away, and lasting only seconds at most. Speculation is that the GRB may be a result of a very massive star collapsing into a black hole, then exploding.
NASA animation showing the collapsing star scenario that is the leading contender to explain gamma-ray bursts.