A CH star in the globular cluster NGC 6426

SHARINA, M.; ARINGER, B.; DAVOUST, E.; KNIAZEV, A.; DONZELLI, C.J.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 1 p. 1 - 2

0035-8711

We report on the serendipitous discovery of a carbon star near the centre of the low-metallicity globular cluster NGC 6426. We determined its membership and chemical properties using medium-resolution spectra. The radial velocity of -159 km s-1 makes it a member of the cluster. We used photometric data from the literature and the COMARCS stellar atmospheric models to derive its luminosity, effective temperature, surface gravity, metallicity, and approximate C, N and O abundance ratios. According to these properties, we suggest that this star is a genuine carbon-rich low-metallicity asymptotic giant branch star.