TY - JOUR

T1 - CNO and Li abundances in Barium-enriched stars

AU - Drake, Natalia A.

AU - Pereira, Claudio B.

PY - 2006/8/1

Y1 - 2006/8/1

N2 - CNO and Li abundances and 12C/13C isotopic ratios have been derived for two metal-poor Ba giants, HD 104340 and HD 206983, and two CH subgiants, HD 50264 and HD 87080. High resolution spectra obtained with the 1.52 m telescope and the FEROS echelle spectrograph at ESO, La Silla, Chile, were used in this study. CNO and Li abundances so as 12C/ 13C isotopic ratios were determined by applying the synthetic spectrum method to the lines of C2, CH, CN, [O I and Li I. Our analysis showed that the giant stars studied here have quite different natures: HD 206983 is a metal-poor barium star while HD 104340, although showing enhancement of s-process elements, should not be considered as a classical barium star: its barium syndrome 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. Light element abundance pattern of HD 104340 resembles anomalies resulting from the appearance on the stellar surface of material enriched in triple- and CNO cycling.

AB - CNO and Li abundances and 12C/13C isotopic ratios have been derived for two metal-poor Ba giants, HD 104340 and HD 206983, and two CH subgiants, HD 50264 and HD 87080. High resolution spectra obtained with the 1.52 m telescope and the FEROS echelle spectrograph at ESO, La Silla, Chile, were used in this study. CNO and Li abundances so as 12C/ 13C isotopic ratios were determined by applying the synthetic spectrum method to the lines of C2, CH, CN, [O I and Li I. Our analysis showed that the giant stars studied here have quite different natures: HD 206983 is a metal-poor barium star while HD 104340, although showing enhancement of s-process elements, should not be considered as a classical barium star: its barium syndrome 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. Light element abundance pattern of HD 104340 resembles anomalies resulting from the appearance on the stellar surface of material enriched in triple- and CNO cycling.

KW - Stars: abundances

KW - Stars: chemically peculiar

KW - Stars: evolution

KW - Stars: individual (HD 50264, HD 87080, HD 104340, HD 206983)

UR - http://www.scopus.com/inward/record.url?scp=36949005223&partnerID=8YFLogxK

U2 - 10.1017/S1743921307000610

DO - 10.1017/S1743921307000610

M3 - Article

AN - SCOPUS:36949005223

VL - 2

SP - 304

EP - 306

JO - Proceedings of the International Astronomical Union

JF - Proceedings of the International Astronomical Union

SN - 1743-9213

IS - S239

ER -