Gravity index (γ) as a function of the surface gravity (log g) for IC 2602. The blue dots are the targets with an effective temperature greater than 5400 K, while the gray dots are those with a T_eff < 5400 K. The solid lines delimit the regions in which a target is considered a giant star based on its γ index (above the horizontal black line) and on its log g value (to the left of the vertical black line).