The thick lines (green and red) are transmission curves of the V and R filters used in the polarimetric observations. Spectra of V4332 Sgr are shown for comparison. The part for λ < 5400 Å is a low-resolution spectrum obtained in October 2005 in SAAO (unpublished). The spectrum covering the remaining wavelength range was obtained with the Subaru Telescope in June 2009 and is described in Kamiński et al. (2010). Spectra are normalized to the peaks of the Na i doublet at 5890 Å.