Boron in the Extreme Pop II Star HD 140283 and the Production of Light Elements in the Early Galaxy

1994/03/01 by B. Edvardsson, B. Gustafsson, S. G. Johansson +4
Physics and Astronomy · #astro-ph

paper · pdf

published as Astron. Astrophys. 290 (1994) 176 · 6 pages, A&A plain TeX, UAO-94-P87

arxiv created 1994/03/01 · arxiv updated 2009/12/01

Abstract

Using observations of the 2496.7 A B I line with the HST GHRS at a nominal resolution of 90,000, we have found the abundance of boron of HD 140283 to be log epsilon_B (= 12 + log (N_B/N_H)) = 0.34 ± 0.20. This result is found when a significant non-LTE effect in the formation of the B I line is taken into account. The resulting N_B/N_Be ratio is about 17 (in the range 9 -- 34), which is in very good agreement with what is expected from spallation by cosmic rays. We conclude that this origin of Be and B in the Early Galaxy is the most probable of recently suggested formation mechanisms. (Submitted to A&A. Postscript figures available via annymous ftp to "chiron.astro.uu.se" in directory pub/Preprints/P87)

Related

• Boron in the very metal-poor star BD-13 3442
• The Abundance of Boron in Evolved A- and B-Type Stars
• Precise boron abundance in a sample of metal-poor stars from far-ultraviolet lines
• The Galactic Evolution of Beryllium and Boron
• Bimodal production of Be and B in the early Galaxy