Notes. First column gives the UT date at the beginning of each observing night. Heliocentric Julian Dates (HJD) at the mid-exposure are given in Cols. 2–4 for each observed Stokes parameter. Mean phase, , and the maximum difference, δϕ, between and phases of individual Stokes parameter observations are presented in Cols. 5–6. Rotational phases were calculated according to our improved ephemeris (Sect. 4.3). The median S/N for each individual Stokes parameter observation are presented in Cols. 7–9. The median S/N was calculated using several orders around λ = 5500 Å where maximum counts were reached.