Missing Stars Outside Millky Way Found

February 19th, 2010

Primitive stars outside our Milky Way galaxy have managed to conceal themselves for years. What this means for the most part is not that they couldn’t see the stars until now, but that they didn’t know which were much older than the other common stars in their view.

“We have, in effect, found a flaw in the forensic methods used until now,” says Else Starkenburg, lead author of the paper reporting the study. “Our improved approach allows us to uncover the primitive stars hidden among all the other, more common stars.”

This discovery is helpful to help determine more about the initial star in the formation of the universe. Meaning that we can now tell the difference and study them in more detain than before. It was like not being able to tell the difference between Ferrari parts and Ford Escort parts before.

Primitive stars are thought to have formed from material forged shortly after the Big Bang, 13.7 billion years ago. They typically have less than one thousandth the amount of chemical elements heavier than hydrogen and helium found in the Sun and are called “extremely metal-poor stars” [1]. They belong to one of the first generations of stars in the nearby Universe. Such stars are extremely rare and mainly observed in the Milky Way.

Cosmologists think that larger galaxies like the Milky Way formed from the merger of smaller galaxies. Our Milky Way’s population of extremely metal-poor or “primitive” stars should already have been present in the dwarf galaxies from which it formed, and similar populations should be present in other dwarf galaxies. “So far, evidence for them has been scarce,” says co-author Giuseppina Battaglia. “Large surveys conducted in the last few years kept showing that the most ancient populations of stars in the Milky Way and dwarf galaxies did not match, which was not at all expected from cosmological models.”