a) CMD of NGC 6139, with its quite short blue HB. In grey we plot all stars, in red all targets observed with FLAMES. The seven UVES stars are indicated by blue open squares; the stars with RV from Saviane et al. (2012) are represented by blue crosses. b) The non-member stars (and the star on the HB) are indicated by red open squares, the stars that are candidate members on the basis of their RV by filled blue squares. The member stars define a reasonably tight RGB, and we indicate with green circles the probable AGB stars (see Sect. 3.1)