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Related papers: Lead abundance in the uranium star CS 31082-001

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The 'First Stars' programme revealed the metal-poor halo star CS 31082-001 to be r-process and actinide rich, including the first measurement of a uranium abundance for an old star. To better characterise and understand such rare objects,…

Solar and Stellar Astrophysics · Physics 2022-02-10 H. Ernandes , B. Barbuy , A. Friaça , V. Hill , 2 M. Spite , F. Spite , B. V. Castilho , C. J. Evans

Detailed abundances of the elements produced by r-process nucleosynthesis in various circumstances are our best observational clues to their origin, since the site(s) of r-element production is(are) still not known with certainty. A small…

We revisit the abundances of neutron-capture elements in the metal-poor ([Fe/H]=-2.9) r-process-rich halo star CS 31082-001. Partly motivated by the development of the new near-ultraviolet Cassegrain U-band Efficient Spectrograph for the…

Solar and Stellar Astrophysics · Physics 2023-07-03 H. Ernandes , M. J. Castro , B. Barbuy , M. Spite , V. Hill , B. Castilho , C. J. Evans

The recent discovery by Cayrel et al. of U in CS 31082-001 along with Os and Ir at greatly enhanced abundances but with [Fe/H]=-2.9 strongly reinforces the argument that there are at least two kinds of SNII sources for r-nuclei. One source…

Astrophysics · Physics 2009-11-06 Y. -Z. Qian , G. J. Wasserburg

The CH star CS 31062-050 ([Fe/H]=-2.42) is one of the most useful stars yet discovered for evaluating the s-process in metal-poor stars. It is very abundant in heavy elements (e.g., [La/Fe]=2.2), and its relatively cool temperature and low…

Astrophysics · Physics 2009-11-10 Jennifer A. Johnson , Michael Bolte

We report the first detection of the Pb II line at 2203.534 Angstroms in three metal-poor stars, using ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We perform a standard…

We obtain age estimates for the progenitor(s) of the extremely metal-poor ([Fe/H = -2.9) halo star CS 31082-001, based on the recently reported first observation of a Uranium abundance in this (or any other) star. Age estimates are derived…

Astrophysics · Physics 2008-11-26 R. Toenjes , H. Schatz , K. -L. Kratz , B. Pfeiffer , T. C. Beers , J. Cowan , V. Hill

We have determined lead (Pb) abundances for twelve red giants having [Fe/H] between -2.1 and -1.3, and its upper-limits for two lower metallicity objects, as well as the abundances of lanthanum (La) and europium (Eu). The averages of…

Astrophysics · Physics 2015-05-13 Wako Aoki , Satoshi Honda

High-resolution spectra obtained with three ground-based facilities and the Hubble Space Telescope (HST) have been combined to produce a new abundance analysis of CS 22892-052, an extremely metal-poor giant with large relative enhancements…

First results are reported of a new abundance study of neutron-capture elements in the ultra-metal-poor (UMP; [Fe/H] = -3.1) halo field giant star CS 22892-052. Using new high resolution, high signal-to-noise spectra, abundances of more…

We present the results of an abundance analysis for a sample of stars with $-4<$[Fe/H]$<-2$. The data were obtained with the HIRES spectrograph at Keck Observatory. The set includes 28 stars, with effective temperature ranging from 4800 to…

Knowing accurate Pb abundances of metal-poor stars provides constraints on the Pb production mechanisms in the early Galaxy. Accurately deriving Th abundances permits a nucleo-chronometric age determination of the star. We improve the…

Astrophysics of Galaxies · Physics 2015-06-04 Lyudmila Mashonkina , Alexander Ryabtsev , Anna Frebel

During an ESO-VLT large program devoted to high-resolution spectroscopy of extremely metal-poor stars selected from the H&K survey of Beers and colleagues, a [Fe/H] giant star was found to be as enriched in neutron-capture r-process…

Astrophysics · Physics 2007-05-23 R. Cayrel

Cowan et al. (2021) review how roughly half the elements heavier than iron found in the Sun are produced by rapid neutron capture and half by slow neutron capture, the r- and s-processes. In the Sun, their relative contribution to…

Solar and Stellar Astrophysics · Physics 2021-06-23 Ruth C. Peterson

We have combined new high-resolution spectra obtained with the Hubble Space Telescope (HST) and ground-based facilities to make a comprehensive new abundance analysis of the metal-poor, halo star BD +17^\circ 3248. We have detected the…

We examine the Pb and Th abundances in 27 metal-poor stars (-3.1 < [Fe/H] < -1.4) whose very heavy metal (Z > 56) enrichment was produced only by the rapid (r-) nucleosynthesis process. New abundances are derived from HST/STIS, Keck/HIRES,…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ian U. Roederer , Karl-Ludwig Kratz , Anna Frebel , Norbert Christlieb , Bernd Pfeiffer , John J. Cowan , Christopher Sneden

We present here the abundance analysis of a metal poor carbon rich lead star, CS29497-030. High resolution and high signal to noise spectra were obtained using the UVES spectrograph on the 8.2m VLT-Kueyen telescope. The observations were…

This paper is part of a larger project in which we systematically study the chemical abundances of Galactic and extragalactic post-asymptotic giant branch (post-AGB) stars. Lead (Pb) is the final product of the s-process nucleosynthesis and…

Solar and Stellar Astrophysics · Physics 2016-02-17 Kenneth De Smedt , Hans Van Winckel , Devika Kamath , Lionel Siess , Stephane Goriely , Amanda I. Karakas , Rajeev Manick

We present detailed abundance observations of the metal-poor ([Fe/H] = --2.0) Galactic halo star BD+17 3248. We have detected gold in this star, for the first time in any halo star. We also detected a weak line at 3859.60 A in the spectrum…

Astrophysics · Physics 2007-05-23 John J. Cowan , Christopher Sneden , James W. Truran

We measured new abundances of so-called light neutron-capture of first peak elements using local thermodynamic equilibrium (LTE) 1D analysis; this analysis resulted in a sample of 11 very metal-poor stars, from [Fe/H]=-2.5 to [Fe/H]=-3.4,…

Solar and Stellar Astrophysics · Physics 2018-04-04 François Spite , Monique Spite , Beatriz Barbuy , Piercarlo Bonifacio , Elisabetta Caffau , Patrick François
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