SPHERE/ZIMPOL images of HD 100546 in the continuum (left panel) and Hα (right panel) filters. The same color code is used for both panels, the numbers in the right-hand legend indicating the linear polarization degree (square root scale). The positions of the central star and candidate c (at a radial distance and PA of ~140 mas and 130°; Currie et al. 2015) are indicated with a white cross and a black circle, respectively, with a size similar to the spatial resolution (~20 mas).