LSD profiles of V806 Tau. Different colours are used for the different observations. The Y-axes are I/Ic, N/Ic, and V/Ic, where Ic is the intensity of the stellar continuum. The I profile represents the total intensity. Stokes V shows a clear Zeeman signature, which corresponds to an actual magnetic detection because the signal is significantly non-null compared to the surrounding noise and the N profile remains flat in the velocity domain.