342 citations · 6.5k across the 144 of their papers we have counts for
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Bright Metal-Poor Stars from the Hamburg/ESO Survey. II. A Chemodynamical Analysis
Timothy C. Beers, Vinicius M. Placco, Daniela Carollo +6
We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B < 14) metal-poor candidates from the Hamburg/ESO Survey. Th…
Observational Constraints on First-Star Nucleosynthesis. II. Spectroscopy of an Ultra Metal-Poor CEMP-no Star
Vinicius M. Placco, Anna Frebel, Timothy C. Beers +6
We report on the first high-resolution spectroscopic analysis of HE0020-1741, a bright (V=12.9), ultra metal-poor ([Fe/H] = -4.1), carbon-enhanced ([C/Fe] = +1.7) star selected fro…
G64-12 and G64-37 are Carbon-Enhanced Metal-Poor Stars
Vinicius M. Placco, Timothy C. Beers, Henrique Reggiani +1
We present new high-resolution chemical-abundance analyses for the well-known high proper-motion subdwarfs G64-12 and G64-37, based on very high signal-to-noise spectra (S/N ~ 700/…
The age structure of the Milky Way's halo
D. Carollo, T. C. Beers, V. M. Placco +7
We present a new, high-resolution chronographic (age) map of the Milky Way's halo, based on the inferred ages of ~130,000 field blue horizontal-branch (BHB) stars with photometry f…
Observational Constraints on First-Star Nucleosynthesis. I. Evidence for Multiple Progenitors of CEMP-no Stars
Jinmi Yoon, Timothy C. Beers, Vinicius M. Placco +6
We investigate anew the distribution of absolute carbon abundance, (C) (C), for carbon-enhanced metal-poor (CEMP) stars in the halo of the Milky Way, based on high-re…
Detection of Phosphorus, Sulphur, and Zinc in the Carbon-Enhanced Metal-Poor Star BD+44 493
Ian U. Roederer, Vinicius M. Placco, Timothy C. Beers
The carbon-enhanced metal-poor star BD+44 493 ([Fe/H]=-3.9) has been proposed as a candidate second-generation star enriched by metals from a single Pop III star. We report the fir…
2MASS J18082002-5104378: The brightest (V=11.9) ultra metal-poor star
Jorge Melendez, Vinicius M. Placco, Marcelo Tucci-Maia +3
Context. The most primitive metal-poor stars are important for studying the conditions of the early galaxy and are also relevant to big bang nucleosynthesis. Aims. Our objective is…
The role of binaries in the enrichment of the early Galactic halo. III. Carbon-enhanced metal-poor stars -- CEMP-s stars
T. T. Hansen, J. Andersen, B. Nordström +4
Detailed spectroscopic studies of metal-poor halo stars have highlighted the important role of carbon-enhanced metal-poor (CEMP) stars in understanding the early production and eje…