SMS evolution on the HR diagram. The colourbar indicates central H mass fractions, X_c, and the shaded red regions show the isoradii lines: the lightest shade corresponds to log (R/R_⊙) = 1 and the darkest shade to log (R/R_⊙) = 4. The white outline around the stellar tracks correspond to the evolutionary stage where the ΩΓ-limit is encountered. Top row: 1000–10 000 M_⊙ stars at initial rotation rates v/v_crit = 0.01 (a), 0.05 (b), and 0.10 (c). Bottom row: comparison of rotation rates at a given mass, 1000 M_⊙ (d), 5000 M_⊙ (e), and 9000 M_⊙ (f).