Evolutionary properties of the 2.2+1.98 M_⊙, P_orb = 69 d system with the enhanced mass loss and for an initial ZAMS surface rotation velocity of 70 km s⁻¹. In the various panels, the solid black and reddotted lines refer to the primary and secondary, respectively. From top to bottom the panels show the Kippenhahn diagram of the primary (a), the evolution of the ratio of the spin to orbital angular velocity (b), of the stellar radii (c), of the surface rotation velocity (d), orbital period (e), and stellar masses (f). The observational constraints are also indicated by the open squares. The estimated age of the system is ~1.26 Gyr.