A high-precision abundance analysis of the nuclear benchmark star HD 20

Journal
Date Issued
2020
Author(s)
Michael Hanke
•
Camilla Juul Hansen
•
Hans-Günter Ludwig
•
•
Andrew McWilliam
•
Eva K. Grebel
•
Luciano Piersanti
DOI
Abstract
We present our chemical abundance investigation of the metal-poor ([Fe/H]=-1.60 dex), r-process-enriched ([Eu/Fe]=0.73 dex) halo star HD 20 using novel and archival high-resolution spectra at outstanding signal-to-noise ratios. By combining one of the first asteroseismic gravity measurements in the metal-poor regime from a TESS light curve with non-LTE analyses of iron lines, we derive a set of highly accurate and precise stellar parameters. These allow us to delineate a chemical pattern comprised of solid detections of 48 elements, including 28 neutron-capture elements, which establishes HD 20 among the few benchmark stars that have almost complete patterns with low systematic dependencies on the stellar parameters. Our light-element (Z<30) abundances are representative of other, similarly metal-poor stars in the Galactic halo with contributions from core-collapse supernovae of type II. A comparison to the scaled solar r-pattern shows that the lighter neutron-capture elements (37
Volume
635
Start page
A104
Uri
Url
Issn Identifier
0004-6361
Ads BibCode
2020A&A...635A.104H
Rights
open.access
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