Lithium abundances in samples of dwarf stars of population II and very old population I

Beckman, J.; Rebolo, R.; Molaro, P.
Bibliographical reference

IN: Advances in nuclear astrophysics; Proceedings of the Second IAP Workshop, Paris, France, July 7-11, 1986 (A87-53676 24-90). Gif-sur-Yvette, France, Editions Frontieres, 1986, p. 29-45.

Advertised on:
0
1986
Number of authors
3
IAC number of authors
2
Citations
6
Refereed citations
3
Description
The CCD camera and Intermediate Dispersion Spectrograph of the 2.5 m Issaac Newton Telescope are used to obtain high quality spectra of the 6708-A Li-7 resonance doublet in 22 dwarfs with metallicities not greater than -0.7. A mean constant value of Log N(Li) = 2.07 (+ or - 0.1) is found for highly metal deficient dwarfs (Fe/H abundance ratios of not greater than 1.5) with atmospheric temperatures T(eff) greater than 5500 K, and a larger spread with values of Log N(Li) up to 2.4 for the warmer dwarfs with metallicities between -0.7 and -1.2. The results agree with previous findings by Spite et al. (1982, 1984) showing a highly uniform Li abundance near the inception of the galaxy. Li depletion appears to set in at higher temperatures for the moderately metal deficient stars than for the extremely metal deficient, consistent with metallicity-dependent depletion rates (low metals, low depletion).