josephpalazzo
Illusion Master
Joined: 30 Aug 2006
Posts: 8036
Local time: 1:04 AM
Location: D-brane
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 Posted: Fri Aug 01, 2008 7:32 am Post subject: Stellar birth |
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The problem with studying those very early stars is that they no longer exist. According to theory, all or nearly all of them began as supergiants hundreds of times more massive than the sun. Then they expended their nuclear fuel and exploded within a few million years. This early demise was good for the evolution of the universe, because the supergiants dispersed the heavy elements necessary to form smaller stars as well as planets and, eventually, people. But unfortunately for scientists, the primordial beasts also expunged all detectable evidence of themselves.
A team led by physicist Naoki Yoshida of Nagoya University in Japan set out to fill this cosmic evolutionary gap in the only way currently possible: They carried out a computer simulation that duplicates the process of star formation in the very young universe. The task actually proved easier than it would have been to simulate stellar evolution in the present day. That's because the current galactic environment is full of magnetic fields and turbulence, both of which greatly complicate the creation of accurate simulations. Not so in the first few million years after the big bang. Back then, all stars needed to form was a primordial soup of mostly hydrogen and some helium atoms, perturbed by the effects of gravity on minuscule differences in the density of the gases, and the mysterious substance known as dark matter.
Read the article at: http://sciencenow.sciencemag.org/cgi/content/full/2008/731/2 |
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