Observations of WD 0708−670 obtained on 2019-10-17 in the presence of strong lunar background. The star’s polarisation (red solid lines) is obtained after subtracting the background contribution (blue solid lines) estimated from different regions of the CCD from the total observed polarisation (black solid lines). In each panel, the value of d refers to thedistance from the source of the region where the background was estimated. See text for more details.