SIMBAD references

From medium-resolution spectra (∼5A) of 5 red supergiants in the globular cluster NGC 1818 of the Large Magellanic Cloud, we have derived their metallicities through a comparison to a grid of 380 synthetic spectra (Cayrel et al. 1991). The carbon abundances were then derived by computing synthetic spectra in the G-band region. A mean metallicity for the 5 stars is [Fe/H]≃-0.9. The mean carbon abundance is ε(C)=7.9 for 4 stars, and a lower value of ε(C)=7.2 for the star B26, for which a convective mixing, or exchange of material with a companion has possibly occurred.