Hertzsprung–Russell diagram of three low-Z evolutionary models that become core-hydrogen-burning SG stars with initial masses of 150, 257, and 575 M_⊙ and initial rotational velocity of 100 km s⁻¹. Dots in the tracks mark every 10⁵ years of evolution. Crosses mark the end of the core-hydrogen-burning phase; in case of the model with 575 M_⊙, the end of the computation. Theoretical mass-loss rates are colour coded, and dashed lines indicate the radial size of the stars on the diagram.