566 citations · 915 across the 9 of their papers we have counts for
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High-Resolution Spectra Observed for SPY. II. DB and DBA Stars
B. Voss, D. Koester, R. Napiwotzki +2
We present a detailed spectroscopic analysis of the stars with helium-dominated spectra in the ESO Supernova Ia Progenitor Survey (SPY). Atmospheric parameters, masses, and abundan…
Discovery of HE 1523-0901, a Strongly r-Process Enhanced Metal-Poor Star with Detected Uranium
Anna Frebel, Norbert Christlieb, John E. Norris +3
We present age estimates for the newly discovered very r-process enhanced metal-poor star HE 1523-0901 ([Fe/H]=-2.95) based on the radioactive decay of Th and U. The bright (V=11.1…
Chemical Abundance Analysis of the Extremely Metal-Poor Star HE 1300+0157
Anna Frebel, John E. Norris, Wako Aoki +5
We present a detailed chemical abundance analysis of HE 1300+0157, a subgiant with [Fe/H]=-3.9. From a high-resolution, high-S/N Subaru/HDS spectrum we find the star to be enriched…
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…
Identification of a DO white dwarf and a PG1159 star in the ESO SN Ia progenitor survey (SPY)
K. Werner, T. Rauch, R. Napiwotzki +3
We present high-resolution VLT spectra of a new helium-rich DO white dwarf and a new PG1159 star, which we identified in the ESO SPY survey. We performed NLTE model atmosphere anal…
Double degenerates and progenitors of supernovae type Ia
R. Napiwotzki, L. Yungelson, G. Nelemans +12
We report on systematic radial velocity surveys for white dwarf - white dwarf binaries (double degenerates - DDs) including SPY (ESO Supernovae Ia progenitor survey) recently carri…