Fit to the average light curve of events A and B (in red) by the two models of the occultation of KIC 8462852 by a planetary ring, as presented in Sect. 5 (black curves). Top panel: homogeneous circular ring with a constant opacity and a non-zero impact parameter. Bottom panel: circular ring with a constant opacity in the centre (red area) and a decreasing opacity with distance following a r^{− α} law in the external ring (blue area). The impact parameter is fixed to 0. The black circle represents the edge of stellar disk.