Mass of the secondary component as a function of the orbital inclination i_o: primary masses M₁ of 1.1 ± 0.5 M_⊙ (left panel; see Table A.2) and 0.315 ± 0.015 M_⊙ (right panel; see Fig. A.6) are used to numerically solve Eq. (1) for M₂. The width of the gray shaded region reflects all 1σ-uncertainties. The y-axis on the right-hand-side shows the luminosity of a zero-age main sequence (ZAMS) star with mass M₂ based on evolutionary tracks for nonrotating stars of solar metallicity (Ekström et al. 2012). The light-blue shaded horizontal bar represents the inferred luminosity of the visible B-type primary, log(L₁/L_⊙). For high orbital inclinations, a relatively unevolved low-mass MS companion could be outshined by its primary by more than one (right panel) to almost two (left panel) orders of magnitude, which could be faint enough to avoid imprints in the observed spectrum.