Determination of the light contributions of θ² Tau AB, using the disentangled component spectra. The grey vertical bars represent the acceptable values for ℓ_B/ℓ_A, for each spectral region (Table 1). The ℓ_B/ℓ_A predicted by AM06 are also shown (i.e. black diamonds with error bars), as well as Eq. (2) (straight black line). The grey line represents the slope of the flux ratio curve of two synthetic spectra with a difference of temperature corresponding to +200 K, in the sense (component B – component A). See Sects. 3 and 4.1.