Lead abundance in the uranium star CS 31082-001
(2004) In Astronomy & Astrophysics 428(1). p.9-12- Abstract
- In a previous paper we were able to measure the abundance of uranium andthorium in the very-metal poor halo giant BPS <ASTROBJ>CS31082-001</ASTROBJ>, but only obtained an upper limit for the abundanceof lead (Pb). We have got from ESO 17 h of additional exposure on thisstar in order to secure a detection of the minimum amount of leadexpected to be present in <ASTROBJ>CS 31082-001</ASTROBJ>, the amountarising from the decay of the original content of Th and U in the star.We report here this successful detection. We find an LTE abundancelog(Pb/H)+12=-0.55 ± 0.15 dex, one dex below the upper limitsgiven by other authors for the similar stars <ASTROBJ>CS22892-052</ASTROBJ> and <ASTROBJ>BD... (More)
- In a previous paper we were able to measure the abundance of uranium andthorium in the very-metal poor halo giant BPS <ASTROBJ>CS31082-001</ASTROBJ>, but only obtained an upper limit for the abundanceof lead (Pb). We have got from ESO 17 h of additional exposure on thisstar in order to secure a detection of the minimum amount of leadexpected to be present in <ASTROBJ>CS 31082-001</ASTROBJ>, the amountarising from the decay of the original content of Th and U in the star.We report here this successful detection. We find an LTE abundancelog(Pb/H)+12=-0.55 ± 0.15 dex, one dex below the upper limitsgiven by other authors for the similar stars <ASTROBJ>CS22892-052</ASTROBJ> and <ASTROBJ>BD +17°3248</ASTROBJ>, alsoenhanced in r-process elements. From the observed present abundances ofTh and U in the star, the expected amount of Pb produced by the decay of<SUP>232</SUP>Th, and <SUP>238</SUP>U alone, over 12-15 Gyr is-0.73± 0.17 dex. The decay of <SUP>235</SUP>U is more difficultto estimate, but is probably slightly below the contribution of<SUP>238</SUP>U, making the contribution of the 3 actinides onlyslightly below, or even equal to, the measured abundance. Thecontribution from the decay of <SUP>234</SUP>U has was not included, forlack of published data. In this sense our determination is a lower limitto the contribution of actinides to lead production. We comment thisresult, and we note that if a NLTE analysis, not yet possible, doublesour observed abundance, the decay of the 3 actinides will stillrepresent 50 per cent of the total lead, a proportion higher than thevalues considered so far in the literature.Based on observations obtained with the Very Large Telescope of theEuropean Southern Observatory at Paranal, Chile. (Less)
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https://lup.lub.lu.se/record/134128
- author
- Plez, B. ; Hill, V. ; Cayrel, R. ; Spite, M. ; Barbuy, B. ; Beers, T. C. ; Bonifacio, P. ; Primas, F. and Nordström, Birgitta LU
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- atomic data, abundances, nucleosynthesis, stars: abundances, physical data and processes: nuclear reactions
- in
- Astronomy & Astrophysics
- volume
- 428
- issue
- 1
- pages
- 9 - 12
- publisher
- EDP Sciences
- external identifiers
-
- wos:000225334900003
- scopus:10044267935
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361:200400094
- language
- English
- LU publication?
- yes
- id
- cd636aef-4a22-4891-b528-7093e17f0c9d (old id 134128)
- date added to LUP
- 2016-04-01 16:40:46
- date last changed
- 2022-12-12 20:34:06
@article{cd636aef-4a22-4891-b528-7093e17f0c9d,
abstract = {{In a previous paper we were able to measure the abundance of uranium andthorium in the very-metal poor halo giant BPS <ASTROBJ>CS31082-001</ASTROBJ>, but only obtained an upper limit for the abundanceof lead (Pb). We have got from ESO 17 h of additional exposure on thisstar in order to secure a detection of the minimum amount of leadexpected to be present in <ASTROBJ>CS 31082-001</ASTROBJ>, the amountarising from the decay of the original content of Th and U in the star.We report here this successful detection. We find an LTE abundancelog(Pb/H)+12=-0.55 ± 0.15 dex, one dex below the upper limitsgiven by other authors for the similar stars <ASTROBJ>CS22892-052</ASTROBJ> and <ASTROBJ>BD +17°3248</ASTROBJ>, alsoenhanced in r-process elements. From the observed present abundances ofTh and U in the star, the expected amount of Pb produced by the decay of<SUP>232</SUP>Th, and <SUP>238</SUP>U alone, over 12-15 Gyr is-0.73± 0.17 dex. The decay of <SUP>235</SUP>U is more difficultto estimate, but is probably slightly below the contribution of<SUP>238</SUP>U, making the contribution of the 3 actinides onlyslightly below, or even equal to, the measured abundance. Thecontribution from the decay of <SUP>234</SUP>U has was not included, forlack of published data. In this sense our determination is a lower limitto the contribution of actinides to lead production. We comment thisresult, and we note that if a NLTE analysis, not yet possible, doublesour observed abundance, the decay of the 3 actinides will stillrepresent 50 per cent of the total lead, a proportion higher than thevalues considered so far in the literature.Based on observations obtained with the Very Large Telescope of theEuropean Southern Observatory at Paranal, Chile.}},
author = {{Plez, B. and Hill, V. and Cayrel, R. and Spite, M. and Barbuy, B. and Beers, T. C. and Bonifacio, P. and Primas, F. and Nordström, Birgitta}},
issn = {{0004-6361}},
keywords = {{atomic data; abundances; nucleosynthesis; stars: abundances; physical data and processes: nuclear reactions}},
language = {{eng}},
number = {{1}},
pages = {{9--12}},
publisher = {{EDP Sciences}},
series = {{Astronomy & Astrophysics}},
title = {{Lead abundance in the uranium star CS 31082-001}},
url = {{https://lup.lub.lu.se/search/files/4747584/624413.pdf}},
doi = {{10.1051/0004-6361:200400094}},
volume = {{428}},
year = {{2004}},
}