activity
20012025
most citedMeasurement of stellar age from uranium decay

381 citations · 876 across the 12 of their papers we have counts for

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9 papers · 1 filter

astro-ph.SR2025

Abundances of P, S, and K in 58 bulge spheroid stars from APOGEE

B. Barbuy, H. Ernandes, A. C. S. Friaça +25

We have previously studied several elements in 58 selected bulge spheroid stars, based on spectral lines in the H-band. We now derive the abundances of the less-studied elements ph…

astro-ph.SR2024

Abundances of iron-peak elements in 58 bulge spheroid stars from APOGEE

B. Barbuy, A. C. S. Friaça, H. Ernandes +22

Stars presently identified in the bulge spheroid are probably very old, and their abundances can be interpreted as due to the fast chemical enrichment of the early Galactic bulge.…

astro-ph.SR2024

The R-Process Alliance: Analysis of Limited-r Stars

T. Xylakis-Dornbusch, T. T. Hansen, T. C. Beers +8

Context. In recent years, the R-Process Alliance (RPA) has conducted a successful search for stars enhanced in elements produced by the rapid neutron-capture (r-)process. In partic…

astro-ph.SR2022★ 20 cited

NLTE analysis of the methylidyne radical (CH) molecular lines in metal-poor stellar atmospheres

S. A. Popa, R. Hoppe, M. Bergemann +3

An analysis of the CH molecule in non-local thermodynamic equilibrium (NLTE) is performed for the physical conditions of cool stellar atmospheres typical of red giants (log g = 2.0…

astro-ph.SR2015★ 62 cited

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…

astro-ph.SR2014★ 6 cited

Chemical abundances of the metal-poor horizontal-branch stars CS 22186-005 and CS 30344-033

S. Caliskan, E. Caffau, P. Bonifacio +5

We report on a chemical-abundance analysis of two very metal-poor horizontal-branch stars in the Milky Way halo: CS 22186-005 ([Fe/H]=-2.70) and CS 30344-033 ([Fe/H]=-2.90). The an…

astro-ph.SR2011★ 53 cited

First stars XIII. Two extremely metal-poor RR Lyrae stars?

C. J. Hansen, B. Nordstroem, P. Bonifacio +11

The chemical composition of extremely metal-poor stars (EMP stars; [Fe/H]<~ -3) is a unique tracer of early nucleosynthesis in the Galaxy. As such stars are rare, we wish to find c…

astro-ph.SR2011★ 50 cited

First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars

Monique Spite, E. Caffau, S. M. Andrievsky +15

Sulfur is important: the site of its formation is uncertain, and at very low metallicity the trend of [S/Fe] against [Fe/H] is controversial. Below [Fe/H]=-2.0, [S/Fe] remains cons…

astro-ph.SR2009★ 98 cited

The Hamburg/ESO R-process Enhanced Star survey (HERES) IV. Detailed abundance analysis and age dating of the strongly r-process enhanced stars CS 29491-069 and HE 1219-0312

W. Hayek, U. Wiesendahl, N. Christlieb +8

We report on a detailed abundance analysis of two strongly r-process enhanced, very metal-poor stars newly discovered in the HERES project, CS 29491-069 ([Fe/H]=-2.51, [r/Fe]=+1.1)…