Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-10-26
Astron.Astrophys. 428 (2004) L9-L12
Astronomy and Astrophysics
Astrophysics
4 pages, LateX, A&A Letters Accepted
Scientific paper
10.1051/0004-6361:200400094
In a previous paper we were able to measure the abundance of uranium and thorium in the very-metal poor halo giant BPS CS 31082-001, but only obtained an upper limit for the abundance of lead (Pb). We have got from ESO 17 hours of additional exposure on this star in order to secure a detection of the minimum amount of lead expected to be present in CS 31082-001, the amount arising from the decay of the original content of Th and U in the star. We report here this successful detection. We find an LTE abundance log(Pb/H)+12=-0.55 \pm 0.15 dex, one dex below the upper limits given by other authors for the similar stars CS 22892-052 and BD +17d3248, also enhanced in r-process elements. From the observed present abundances of Th and U in the star, the expected amount of Pb produced by the decay of 232Th, and 238U alone, over 12-15 Gyr is -0.73\pm 0.17 dex. The decay of 235U is more difficult to estimate, but is probably slightly below the contribution of 238U, making the contribution of the 3 actinides only slightly below, or even equal to, the measured abundance. The contribution from the decay of 234U has was not included, for lack of published data. In this sense our determination is a lower limit to the contribution of actinides to lead production. We comment this result, and we note that if a NLTE analysis, not yet possible, doubles our observed abundance, the decay of the 3 actinides will still represent 50 per cent of the total lead, a proportion higher than the values considered so far in the literature.
Barbuy Batriz
Beers Timothy C.
Bonifacio Piercarlo
Cayrel Roger
Hill Vanessa
No associations
LandOfFree
Lead abundance in the uranium star CS 31082-001 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Lead abundance in the uranium star CS 31082-001, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lead abundance in the uranium star CS 31082-001 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-497826