14 April 2005
Low-metal stars: second site
When HE0107–5240 was discovered in 2002 it was the most metal-deficient star known. (Astrophysicists use the term 'metal' for all elements bar hydrogen and helium.) It had an iron abundance 20 times lower than previously recorded, suggesting that here was a relic, a star formed soon after the Big Bang. Now a second 'unevolved' star has been discovered: HE1327–2326, with an iron abundance about half that of HE0107–5240. One low-metal star was a novelty; two is a new class of stellar object. The similarities (in C and N content) and contrasts (in Li and Sr) between these two stellar relics present challenges to theories of star formation and may lead to new discoveries about how the elements were synthesized in the first stars.
Nucleosynthetic signatures of the first stars
ANNA FREBEL et al.
Nature 434, 871–873 (2005); doi:10.1038/nature03455
| First Paragraph | Full Text (HTML / PDF) |
Astrophysics: Two's company
ROGER CAYREL
Nature 434, 838 (2005); doi:10.1038/434838a
| Full Text (HTML / PDF) |
