January 2nd, 2009
“95% of the mass in galaxies and clusters of galaxies is in the form of an unknown type of dark matter,” say Katherine Freese at the University of Michigan, Ann Arbor, and buddies. What effect might this huge amount of stuff have on star formation?
The answer according to these guys is astounding. In the early universe, the first stars would have been powered by dark matter.
Here’s the thinking: the concentration of dark matter at that time would have been extremely high meaning that any ordinary stars would naturally contain large amounts of dark matter. Freese and co have calculated the effect of this stuff and say tit would have radically altered the evolution of these stars forming so-called “dark stars”.
Dark stars would have been driven by the annihilation of dark matter particles releasing heat but only in stars larger than 400 solar masses. That turns out to be quite feasible since stars containing smaller amounts of dark matter would naturally grow as they swept up dark matter from nearby space.
When the dark matter runs out, they simply collapse to form black holes
Interestingly, we should soon be able to to see these stars with forthcoming generations of telescopes. And if they are found, that would be further proof of the existence of dark matter.
Keep ‘em peeled!
Ref: arxiv.org/abs/0812.4844: Dark Stars: the First Stars in the Universe May be Powered by Dark Matter Heating
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