The Na-O anticorrelation in horizontal branch stars. IV. M 22
We obtained high-resolution spectra for 94 candidate stars belonging to the HB of M 22 with FLAMES. Previous works have indicated that this cluster has split subgiant (SGB) and red giant branches (RGB) and hosts two different stellar populations, differing in overall metal abundance and both exhibiting a Na-O anti-correlation. The HB stars we
Gratton, R. G. et al.
Fecha de publicación:
3
2014