Hertzsprung-Russel diagram and time evolution of the stellar masses, radii, effective temperatures, Roche-lobe filling factor, and the orbital period for the binary evolution track that best reproduces the observed parameters of the system. This track was computed for an initial orbital period P_orb, 0 = 1.05 d, primary and secondary masses M_don, 0 = 1.94 M_⊙ and M_acc, 0 = 0.94 M_⊙, metallicity Z = 0.014, overshooting parameter f_ov = 0.02, mixing-length parameter α_MLT = 1.5, and mass-transfer efficiency β = 0.2. The evolutionary tracks of the accretor and the donor are shown with orange and blue lines, respectively, and the same colors are used to indicate the observed ranges of the corresponding parameters, which are marked with shaded bands in the plots. The model at the time corresponding to the observed orbital period is marked with vertical dashed lines in the lower panels and with circular markers in the HR diagram.