2008AJ....135.1070D

We derive carbon, nitrogen, oxygen, and lithium abundances as well as ¹²C/¹³C isotopic ratios in two chemically peculiar red giant stars: HD 104340 and HD 206983. The abundances were determined via spectrum synthesis of optical high-resolution spectra containing C₂, CH, CN, [O I], and Li I lines. Our results indicate that HD 206983 is a barium star, while HD 104340, although showing enhancements of s-process elements, should not be considered as a classical barium star: its barium star nature can be explained by internal nucleosynthesis. The low metallicity giant HD 104340 can experience deeper convective mixing and, consequently, a larger dredge-up of CNO-cycle products compared to normal red giants. The light element abundance pattern of HD 104340 resembles anomalies resulting from the appearance on the stellar surface of material enriched by triple-α and CNO cycling.