Evolutionary tracks for stars of 7 M_⊙ (lower curve) and 10 M_⊙ (upper curve) that initially rotate at 60% of the critical velocity, taken from Ekström et al. (2012). The horizontal solid lines indicate the luminosity of the star at the beginning of the He-burning phase for the rotating case illustrated in the figure, and the dotted lines show the same for the nonrotating models. Although the luminosity and therefore the derived mass is only weakly dependent on the initial rotation velocity, the age at which the He-burning stage is reached is significantly older for a rotating star than in the nonrotating case.