Evolution of intensity of the total brightness B (top panel), polarized brightness pB (mid panel), and F-corona F_inv (bottom panel) measured in the pixel (r = 2.6 R_⊙, ϕ = 119°) in a sequence of LASCO-C2 images. The dashed green line in the top panel shows the pB profile re-scaled according to the linear model best fitting the B-pB regression (see Fig. 4). The third panel shows the intensity of the F-corona F_inv calculated using the inversion method (see Sect. 3.1 for details). The x-axis is in units of days and covers one month (June 2001), whereas the y-axis is in MSB units. The Pearson’s correlation coefficient of the total and polarized brightness (ρ_B, pB) is equal to 1.