Tracks in M_bol vs. Log plane for BSG stages, using both a modified and unmodified bolometric magnitude due to the presence of the secondary. Grey tracks are original tracks with unmodified M_bol (as in Fig. 3). Blue, green and red tracks correspond to the first, second and third BSG stages with modified M_bol calculated by combining the V band flux of the primary and secondary and applying the bolometric correction (BC) based on the log g and T_eff of the primary. Maroon tracks use a modified M_bol calculated by computing the bolometric magnitude for the sum of the luminosities of the primary and secondary. Top panel: close-up track of the 15 M_⊙ model to more clearly illustrate the changes in the modified tracks. Bottom panel: models with initial masses of 12, 15, 20 and 30 M_⊙, mass ratio of q = 0.9 and initial period of log(P/days) = 3.0.