http://www.sciencedaily.com/releases/2006/10/061004151431.htm-----
The death of a massive nearby star billions of years ago offers evidence the sun was born in a star cluster, say astronomers at the University of Illinois at Urbana-Champaign. Rather than being an only child, the sun could have hundreds or thousands of celestial siblings, now dispersed across the heavens.
In a paper accepted for publication in the Astrophysical Journal, astronomy professors Leslie W. Looney and Brian D. Fields, and undergraduate student John J. Tobin take a close look at short-lived radioactive isotopes once present in primitive meteorites. The researchers' conclusions could reshape current theories on how, when and where planets form around stars.
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"The supernova was stunningly close; much closer to the sun than any star is today," Fields said. "Our solar system was still in the process of forming when the supernova occurred."
The massive star that exploded was formed in a group or cluster of stars with perhaps hundreds, or even thousands, of low-mass stars like the sun, Fields said. Because the stars were not gravitationally bound to one another, the sun's siblings wandered away millennia ago.
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