Abundances of Lithium, Beryllium, and Lead in the Solar Atmosphere.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Abundances of Lithium, Beryllium, and Lead in the Solar Atmosphere. Mutschlecner, J. P. Abstract A redetermination has been made of the abundances of the elements lithium, beryllium, and lead in the solar atmosphere. The observational material consisted of numerous spectral scans obtained with the vacuum spectrograph of the McMath-Hulbert Observatory. Exact curves of growth were computed for each line using digital-computer programs. Features of the theoretical calculations include (1) the use of a newly derived semiempirical solar model atmosphere, (2) the inclusion of an empirically determined component of the continuous absorption coefficient in those regions where it was required, (3) an analysis of the influence of various uncertainties on the curve of growth and hence on the derived abundances. The resulting abundances on the silicon scale (i.e., number of atoms per million Si atoms) are: N(Li)=1.1, N(Be)=6.9, N(Pb)=1.4. An analysis of the source of errors shows that basic uncertainties in the solar model probably produce the largest abundance uncertainties. The upper limit to the combined error due to all sources is about 100% for lithium and lead and about 30% for beryllium. The beryllium and lead values are in good accord with meteoritic determinations while the solar lithium value is as little as 2% of meteoritic abundances. It is impossible at present to derive any conclusions as the depth of the solar convective zone from the lithium and beryllium abundances because of poor knowledge of the past history of the convective zone. The lead abundance is in reasonable agreement with a semi-theoretical prediction of the abundance by Clayton et al. EAnn. Phys. (N.Y.) 12, 331, 1961J based upon a detailed analysis of the s-process for nuclear synthesis. This work was done under auspices of University of Michigan Astronomy Department, Ann Arbor, Michigan, in partial fulfillment of Ph.D. ~equirements. Publication: The Astronomical Journal Pub Date: June 1963 DOI: 10.1086/109148 Bibcode: 1963AJ.....68S.287M full text sources ADS |