4 papers
TOPoS VII. Age-metallicity relation in the Galactic halo and assembly of the Milky Way
P. Bonifacio, Y. Lebreton, I. Koutsouridou +8
One technique for determining stellar ages is to compare the position of a star in the Hertzsprung-Russell diagram to theoretical stellar evolutionary tracks. The sub-giant evoluti…
TYC 170-1218-1: A new r-process-enhanced extremely metal-poor star, rich in Th
E. Caffau, P. Bonifacio, L. Sbordone +5
Context . Extremely metal-poor (EMP) stars are formed from gas clouds enriched by one or a few supernova explosions belonging to the first stellar generation and this very limited…
Unveiling the nature of HE 0107-5240
E. Caffau, M. Steffen, P. Molaro +27
The vast majority of the most iron-poor stars in the Galaxy exhibit a strong carbon enhancement, with C/H ratios only about two orders of magnitude below solar. This unusual chemic…
A Sequoia stellar candidate with very high 7Li and 9Be
L. Monaco, E. Caffau, P. Molaro +2
Aims. The metal-poor star BPM 3066 belongs to the retrograde halo and presents unexpectedly strong spectral features of lithium. To gain insight into the origin of this peculiar ab…