Positions in Hertzsprung-Russell diagram of the subsample of 620 stars for which we derived spectroscopic parameters. The three host stars we focus on in the present paper are highlighted as red dots. We adopted the luminosities obtained with the method described in Sect. 3.2. The evolutionary tracks are from models of Pietrinferni et al. (2004) for different stellar masses (1.0, 1.2, 1.5, 1.7, 2.0, 2.5, 3.0, 4.0, and 5.0M_⊙ from bottom to top). They are for models with solar metallicity.