Telescopes solve 2,000-year-old stellar mystery

CAPE CANAVERAL, Fla. (AP) ? Astronomers finally know why the first documented supernova was super-sized.

The exploded star was observed by the ancient Chinese in the year 185, and visible for eight months. It was later found to be a bigger-than-expected supernova remnant, 8,000 light years away. Each light year is about 6 trillion miles.

New observations in the infrared show the explosion took place in a cavity in space. The cavity allowed the stellar shrapnel to shoot faster and farther out into the universe.

The star ? similar to our sun ? died peacefully and turned into a dense white dwarf. It sucked up material from another star, and then exploded in a supernova.

NASA announced the findings Monday. Four space telescopes were used in the study.

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Online:

NASA: http://www.nasa.gov/mission_pages/spitzer/multimedia/pia14872.html