Azimuthal dependence of the polarized flux from the dust disk around HD 169142. Top: radially integrated polarized flux Q_ϕ(ϕ) for 8° wide angles for the inner (30 − 60 px) and outer (110 − 300 px) ring and the total disk (30 − 300 px) as a function of azimuthal angle ϕ. Bottom: separation r_max(ϕ) of the Q_ϕ peak flux r_max = max_r(Q_ϕ(r)) in 20° angle intervals for the inner and outer dust ring. The red curve is a simple fit of a circle with a 2.5 px center offset (1 px = 3.6 mas). The major (darker) and minor axis position are marked with vertical gray lines.