Hertzsprung-Russell diagram: evolutionary tracks of Clés models with initial masses of 30.0 (green), 31.0 (light blue), and 32.0 M_⊙ (pink), overshooting parameter of 0.20, Z = 0.015, and no turbulent diffusion. Stellar mass-loss was computed according to the formalism of Vink et al. (2001), with ξ = 1. The three dots over-plotted on the corresponding tracks correspond to the models that fit the observational k₂. The observational value is represented by the red point and its error bars, computed through the effective temperature and the radius, are represented by the dark red parallelogram.