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Discovery of HE 152...
Discovery of HE 1523-0901, a strongly r-process-enhanced metal-poor star with detected uranium
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Frebel, Anna (författare)
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- Christlieb, Norbert (författare)
- Uppsala universitet,Institutionen för astronomi och rymdfysik
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Norris, John E. (författare)
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Thom, Christopher (författare)
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Beers, Timothy C. (författare)
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Rhee, Jaehyon (författare)
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visa färre...
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(creator_code:org_t)
- 2007
- 2007
- Engelska.
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 660:2, s. L117-L120
- Relaterad länk:
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https://urn.kb.se/re...
Abstract
Ämnesord
Stäng
- 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) giant was found among a sample of bright metal-poor stars selected from the Hamburg/ESO Survey. From an abundance analysis of a high-resolution (R = 75,000) VLT/UVES spectrum, we find HE 1523 - 0901 to be strongly overabundant in r- process elements ([r/Fe] = 1.8). The abundances of heavy neutron-capture elements (Z > 56) measured in HE 1523 - 0901 match the scaled solar r- process pattern extremely well. We detect the strongest optical U line at 3859.57 angstrom. For the first time, we are able to employ several different chronometers, such as the U/Th, U/Ir, Th/ Eu, and Th/Os ratios to measure the age of a star. The weighted average age of HE 1523 - 0901 is 13.2 Gyr. Several sources of uncertainties are assessed in detail.
Ämnesord
- NATURVETENSKAP -- Fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences (hsv//eng)
Nyckelord
- early universe
- Galaxy : halo
- nuclear reactions
- nucleosynthesis
- abundances
- stars : abundances
- stars : individual (HE 1523-0901)
- Physics
- Fysik
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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