Excess absorption spectra without thermospheric sodium, as a function of wavelength in the stellar rest frame, computed with the different reference spectra mentioned in Sect. 3.1. We display results for two v_eq sin(i) values as well as for two sky-projected spin-orbit angles. The vertical grey lines mark the transition wavelength of Na I D2. For comparison the horizontal dashed grey lines mark the highest and lowest values of the POLD, obtained for λ = 0°.