Orbital profiles of the observed and intrinsic polarization of Cyg X-1. Left panels: observed PD, P, (top panel) and PA, θ, (bottom panel) of Cyg X-1 in the V band, folded with the orbital period. The blue circles correspond to the data obtained in 2022. The red crosses correspond to the PMO data obtained in 1975–1987. Each point corresponds to the average value, calculated within a phase bin of width Δϕ = 1/18. The typical 1σ uncertainty is smaller than the symbol size. Right panels: same as the left panel, but showing the intrinsic polarization of Cyg X-1.