Example of a WDMS binary spectrum (blue line) obtained from the combination of the individual spectra of a WD (green line) and a MS star (red line). The effective temperatures and surface gravities are. respectively, 9250 K and 7.75 dex for the WD, and 2700 K and 5.5 dex for the MS star. As seen, the blue part of the spectrum is dominated by the WD, while the red part has clear M star spectral lines.