Spectra of χ Cyg on September 4, 2007 around the three lines of Ca II triplet in the near-infrared. As in Fig. 2, the black thin line represents intensity (ordinates at right) and Stokes Q and U are shown in red and blue, respectively. The quantity Q has been shifted 0.01 units for clarity. The lines are split into a blue-shifted emission and a red-shifted absorption. The polarisationchanges sign accordingly as if dominated by the amplification of anisotropy in the presence of velocity gradients.