SN 2006gy: A supernova in the galaxy NGC 1260, about 238 million light years away.
Caption: SN 2006gy is the brightest stellar explosion ever recorded and may be a long-sought new type of supernova, according to observations by NASA's Chandra X-ray Observatory (bottom right panel) and ground-based optical telescopes (bottom left). This discovery indicates that violent explosions of extremely massive stars, depicted in the artist's illustration (top panel), were relatively common in the early universe. These data also suggest that a similar explosion may be ready to go off in our own Galaxy.
Scale: Each bottom panel is 2.75 arcsec across.
Chandra X-ray Observatory ACIS Image