Polarimetric and photometric evolution of SN 2008D/XT 080109 (panels a), c), e)) and SN 2007uy (panels b), d), f)). For consistency we used the same symbols as in Fig. 1. The long-dashed lines indicate the position of the barycentre (〈Q〉 ,  〈U〉) of each SN. The two bottom panels e) and f) show the V-band light curves of SN 2008D/XT 080109 and SN 2007uy uncorrected for Galactic reddening. None of the two SNe seem to obey any obvious smooth long-term polarimetric evolution correlated with their optical light curves.