Sun part of a Solar Family... Oct 24, 2006 23:04:48 GMT -6
Post by Chicago Astronomer Joe on Oct 24, 2006 23:04:48 GMT -6
Our Sun Had Sisters
The Sun had sisters when it was born, according to new research, hundreds to thousands of them.
And at least one was a supernova, providing further support for the idea that there could be lots of planets around other stars since our solar system emerged in such an explosive environment.
"We know that the majority of stars in our galaxy were born in star clusters," said Leslie Looney, who arrived at the solar sibling finding along with his colleagues at the University of Illinois at Urbana-Champaign. "Now we also know that the newborn solar system not only arose in such a cluster, but also survived the impact of an exploding star. This suggests that planetary systems are impressively rugged and may be common in even the most tumultuous stellar nurseries."
The evidence for the solar sisters was found in daughters—such as decayed particles from radioactive isotopes of iron—trapped in meteorites, which can be studied as fossil remnants of the early solar system.
These daughter species allowed Looney and his colleagues to discern that a supernova with the mass of about 20 suns exploded relatively near the early Sun when it formed 4.6 billion years ago; and where there are supernovas or any massive star, you also see hundreds to thousands of sun-like stars, he said.
The cluster of thousands of stars dispersed billions of years ago due to a lack of gravitational pull, Looney said, leaving the sisters "lost in space" and our Sun looking like an only child ever since, he said.
The research will be detailed in the Astrophysical Journal.
It makes sense that stars formed in groups and not alone.