Narrator (Megan Watzke, CXC): In 1995 or 1996 a supernova exploded in a nearby galaxy, but no one on Earth knew it at the time. By using the vast amounts of online data now available, a team of astronomers was able to piece together this cosmic case over a decade later. A Chandra observation in 2001 started things off by showing that this object was a bright source that was changing in its X-ray brightness. This led to an investigation that involved some 18 different telescopes on the ground and in space. Ultimately, astronomers realized that this object - now known as supernova 1996cr - was one of the nearest and brightest to have gone off in the last 25 years.
Revised: October 31, 2008