Hertzsprung-Russell diagram: evolutionary tracks of three GENEC models with an initial mass of 32.8 M_⊙, overshooting parameter 0.20, Z = 0.015, and ξ = 1 for the single version (blue) and binary version (green) – both with initial rotational velocity v_eq,ini = 100 km s⁻¹ – and the single version with zero initial rotational velocity (v_eq,ini = 0 km s⁻¹, violet). Two Clés models with an initial mass of 32.8 M_⊙, α_ov = 0.20, Z = 0.015, and ξ = 1 – one without turbulent diffusion (pink) and one with D_T = −2.41 × 10⁷ cm² s⁻¹ (orange) – are also presented for comparison. The dots on the corresponding tracks correspond to the models that fit the observational k₂. The red point indicates the observationally determined value, while the dark red parallelogram indicates the associated error box.