Low-mass “First Stars”?

By Michael on September 16, 2007 at 11:44 pm | In Blog Posts, Dark Matter |

The BBC reports: Dark matter clues in oldest stars:

“In cold dark matter the particles move very slowly; in warm dark matter they move very quickly,” he explained.

“We found that if the dark matter consists of these fast moving particles, then the first stars form in very long, thin filaments…Some of the stars that formed within the filaments would have had a relatively low mass, which is of interest to astronomers as they have a long lifespan and could still survive today.

Dr Theuns added: “In stark contrast, what happens in (the simulation with) cold dark matter is very, very different. Here, the first stars formed in little lumps of dark matter, and just one star per dark matter lump. And these stars are probably very massive as well: 100 solar masses. Because these stars are so massive, they die very quickly; so you wouldn’t find such stars in the Milky Way today,” he said.

Everything I’ve read about the “1st stars” (or Population III stars) is that they would have been very massive because they lack metals (elements heavier than Helium). The stars that followed them (Pop. II and Pop. I) had access to heavier elements created by the supernovae of the Pop. III stars and evolved differently as a result.

What’s important here, as I read it, is that we have a “1st stars” option which creates low-mass stars that could still exist today. So finding such stars could tell us something about dark matter.