Where Have All The Milky Way's Early Stars Gone?- Our Galaxy has a curious lack of pristine stars

The Big Bang produced a Universe filled almost exclusively with hydrogen and helium; all other elements - what astronomers call metals - were produced by stars, supernovae and everything that happens later. So if you can pick out a pristine star with no metals polluting it from among the billions in the Milky Way, then you are likely to have a star dating from our Galaxy's earliest days.

- By Chris Lintott

Our Galaxy has a curious lack of pristine stars. The quest for the oldest star in the Milky Way has been going on for decades. A new paper, from a team led by Edinburgh's Britton Smith, suggests that we might already have got as close as we ever will.

The secret to this form of big game hunting is to look for stars with very few heavy elements. The Big Bang produced a Universe filled almost exclusively with hydrogen and helium; all other elements - what astronomers call metals - were produced by stars, supernovae and everything that happens later. So if you can pick out a pristine star with no metals polluting it from among the billions in the Milky Way, then you are likely to have a star dating from our Galaxy's earliest days.