H-R diagram of the giant star sample. The right panel is a close-up of the area where the stars in the sample are located. Open circles represent RGB stars and filled circles are HB stars. The tracks plotted have [Fe/H] = 0.0 and the different colours represent different phases in the stellar evolution. Grey lines represent the stages before the main sequence evolution (up to the TAMS, Table 2), and right after the end of core helium burning (TACHeB). For the meaning of the abbreviations and EEP number, see Table 2.