839 citations · 4.1k across the 71 of their papers we have counts for
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The role of binaries in the enrichment of the early Galactic halo. II. Carbon-Enhanced Metal-Poor Stars - CEMP-no stars
T. T. Hansen, J. Andersen, B. Nordström +4
The detailed composition of most metal-poor halo stars has been found to be very uniform. However, a fraction of 20-70% (increasing with decreasing metallicity) exhibit dramatic en…
Abundances of carbon-enhanced metal-poor stars as constraints on their formation
C. J. Hansen, B. Nordstroem, T. T. Hansen +6
An increasing fraction of carbon-enhanced metal-poor (CEMP) stars is found as their iron abundance, [Fe/H], decreases below [Fe/H] = -2.0. The CEMP-s stars have the highest absolut…
HE 0017+0055 : A probable pulsating CEMP-rs star and long-period binary
A. Jorissen, T. Hansen, S. Van Eck +6
A radial-velocity monitoring of the Carbon-Enhanced Metal-Poor (CEMP) star HE 0017+0055 over 8 years with the Nordic Optical Telescope and Mercator telescopes reveals variability w…
The role of binaries in the enrichment of the early Galactic halo. I. r-process-enhanced metal-poor stars
T. T. Hansen, J. Andersen, B. Nordstrøm +3
The detailed chemical composition of most metal-poor halo stars has been found to be highly uniform, but a minority of stars exhibit dramatic enhancements in their abundances of he…
Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars
Vinicius M. Placco, Timothy C. Beers, Inese I. Ivans +14
We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the bright carbon-enhanced metal-poor (CEMP) stars HD196944 (V = 8.40, [Fe/H] = -2.41)…
An Elemental Assay of Very, Extremely, and Ultra Metal-Poor Stars
T. Hansen, C. J. Hansen, N. Christlieb +8
We present a high-resolution elemental-abundance analysis for a sample of 23 very metal-poor (VMP; [Fe/H] < -2.0) stars, 12 of which are extremely metal-poor (EMP; [Fe/H] < -3.0),…