Comet Collisions Explain 17-Year-Old Stellar Mystery

ScienceDaily (Nov. 8, 2012) — Every six seconds, for millions of years, comets have been colliding with one another near a star in the constellation Cetus called 49 CETI, which is visible to the naked eye.

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Artist's rendition of a rocky planet being bombarded by comets. (Credit: NASA/JPL-Caltech)

Over the past three decades, astronomers have discovered hundreds of dusty disks around stars, but only two -- 49 CETI is one -- have been found that also have large amounts of gas orbiting them.

"We now believe that 49 CETI is 40 million years old, and the mystery is how in the world can there be this much gas around an otherwise ordinary star that is this old," said Benjamin Zuckerman, a UCLA professor of physics and astronomy and co-author of the research, which was recently published in the Astrophysical Journal. "This is the oldest star we know of with so much gas."

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Sources: University of California at Los Angeles, ScienceDailly.com .

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