Abstract
Recent spectroscopic surveys have revealed a large number of
extremely metal-poor stars in the Galactic halo. Many of these stars are being
subjected to detailed spectroscopic analysis, and a surprisingly large fraction,
about 25 %, turn out to be carbon-rich stars with enhancements of C by as much
as a factor 100. The majority of these carbon-enhanced metal-poor (CEMP)
stars also show enhancements of heavy s-process elements, in particular of lead.
Many of these stars have been found to be spectroscopic binary systems. Their
binarity and abundance patterns strongly suggest that most, possibly all, CEMP
stars have been polluted by a companion star while in an advanced stage of
evolution, which has long since faded away. They provide strong indications
that (1) binary stars were as common among very low-metallicity populations
as they are in the Galactic disk and (2) binaries may have played an important
role in shaping the abundance patterns of the earliest generations of stars.
| Original language | Undefined/Unknown |
|---|---|
| Title of host publication | Stellar evolution at low metallicity : mass loss, explosions, cosmology : proceedings of a meeting held in Tartu, Estonia, 15-19 August 2005 |
| Editors | Henny J.G.L.M. Lamers |
| Place of Publication | San Francisco |
| Publisher | Astronomical Society of the Pacific |
| Pages | 233 |
| Number of pages | 1 |
| Publication status | Published - 2006 |