Star research sheds new light; Sun born in cluster, professors say

By Matthew Richardson

Research done by professors at the University indicates that our sun may have been born with hundreds, possibly even thousands, of other stars similar in size.

Professors Leslie Looney and Brian Fields along with John Tobin, who was then an undergraduate in LAS, studied meteorites from exploded stars called supernovas.

When a star explodes, it shoots radioactive meteorites out into space. The researchers took the meteorites and compared the amount of radioactivity left in them. Because radioactivity decays over a specific amount of time, the three researchers were able to pinpoint how far from our solar system this supernova was.

“This supernova had to be really close,” said Fields, who studies exploding stars. “Supernovas are rare things; they live lifestyles of the rich and famous, they live fast and die young. This means that we had to be next door to a place where stars are born.”

The researchers’ findings were accepted, and will be printed some time next year, by the Astrophysical Journal, which is published by the University of Chicago Press.

“I’m very excited to have the article get published,” said Tobin, now a doctoral candidate in astronomy at the University of Michigan – Ann Arbor.

This research could imply that most stars, like our sun, are born in clusters, and also that the concept of stars forming in isolation, as was assumed about our sun for the last 100 years, is actually rare. Along with star formation, the researchers’ findings have the potential to influence theoretical astrophysics, as well as models for how stars collapse.

“There are actually two possible views: one is that this supernova is actually the event that led to the birth of our sun, but the one that we believe is much more likely is that our sun was born with this supernova,” Fields said.

The research also might give scientists more information to work with when looking at the development of planetary systems.

“If we’re right, it says that while the sun was forming and earth was forming, we (both earth and the sun) survived that explosion,” Fields said. “The fact that the planetary systems survived, means that the planetary systems are pretty rugged.”

“It’s interesting because we live on Earth, meaning that there’s potential that more stars have planetary systems” said Looney, whose research deals with young stars, and how proto-planetary discs, the bodies that become planets, form around them.

“If our findings are correct, then we have to think about star formation in a new way, and the formation of us in a new way,” Looney said.