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)
Please use this url to cite or link to this publication:
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
- 2024-04-12 04:13:31
@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}}, }