www.nasa.gov/mission_pages/swift/bursts/oddball_burst.html
"Scientists using NASA's Swift satellite have detected a new kind of cosmic explosion. The event appears to be a precursor to a supernova, which is expected to reach peak brightness in one week.
The explosion has the trappings of a gamma-ray burst, the most distant and powerful type of explosion known. Yet this explosion, detected on February 18, was about 25 times closer and 100 times longer than the typical gamma-ray burst. And it possesses characteristics never seen before."
  