The chemical compositions of 36 metal-poor red giants are determined, using model-stellar-atmosphere analysis techniques, and discussed on the basis of image-tube echelle spectrograms obtained with the 4-m telescopes at Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory. By forcing Fe I and Fe II to yield the same iron abundances, the spectroscopic stellar-surface gravities are found. The resulting gravities are about 0.25 dex lower than expected for 0.7 solar-mass stars with the luminosities of red giants in metal-deficient globular clusters like M92. The well-known overall enhancements of the light metals (Na through Ti, except for Sc), and the deficiencies of the heavy s-process elements (Sr, Y, Zr, and Ba) in iron-poor stars are confirmed by abundance analyses. The abundance trends revealed by the observational material are described, and the implications for nucleosynthesis during halo formation are discussed.
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Luck et al. (1985) studied this question.