From top to bottom and left to right: (1) Best-fit model of VFTS 042 primary (red line) compared with the disentangled spectrum (black line), (2) determination of the T_eff and log g via the chi-square map for this star. The red cross indicates the position of the minimum χ², (3) and (4) same as for (1) and (2), but for the secondary. (5) Spectral Energy Distribution of VFTS 042. (6) Comparison between the disentangled spectra (scaled by the brightness factor of each component and shifted by their radial velocities) and one observed spectrum (7) Individual HRD (Left) and (8) log g–T_eff diagram of the stars of VFTS 042.