566 citations · 572 across the 3 of their papers we have counts for
7 papers
Nucleosynthetic signatures of the first stars
Anna Frebel, Wako Aoki, Norbert Christlieb +16
The chemically most primitive stars provide constraints on the nature of the first stellar objects that formed in the Universe; elements other than hydrogen, helium and traces of l…
On the Binarity of Carbon-Enhanced, Metal-Poor Stars
S. Tsangarides, S. G. Ryan, T. C. Beers
We report on a programme to monitor the radial velocities of a sample of candidate and confirmed carbon-enhanced, metal-poor (CEMP) stars. We observed 45 targets using the Echelle…
Carbon-rich, extremely metal-poor Population II stars
Sean G. Ryan
A significant fraction of very metal-poor stars have unexpectedly high carbon abundances. I recap on their discovery, describe the results of high-resolution spectroscopic studies…
s- and r-process elements in two very metal-poor stars
Sean G. Ryan, Wako Aoki, Lisa A. J. Blake +5
New measurements of neutron-capture elements are presented for two very metal-poor stars ([Fe/H] ~ -3). One (LP 625-44) has an s-process signature believed to be due to mass transf…
Abundances in Very Metal-Poor Stars
Sean G. Ryan
Metal-poor stars provide information on the characteristics and chemical evolution of the halo population of the Galaxy, the first epoch of star formation and Galaxy formation (not…
7Li in Metal-Poor Stars: The Spread of the Li Plateau
Sean G. Ryan
A highly homogeneous study of 23 halo field dwarf stars has achieved a Li abundance accuracy of 0.033 dex per star. The work shows that the intrinsic spread of the Li abundances of…