Subgiant CH stars. II: Chemical compositions and the evolutionary connection with barium stars

Though model-atmosphere analyses of high-resolution photographic echelle spectrograms, chemical abundances in 15 subgiant CH stars, five barium stars, and four objects classified as metal-deficient barium stars have been determined. The stars in each of these groups show enhanced surface abundances of carbon and the very heavy elements produced by s-process neutron-capture reactions. The atmospheric parameters of subgiant CH stars are found to be typical of F- and G-type main-sequence stars and subgiants. Barium stars are more luminous G- and K-type stars.