Light curves in the form of normalized flux versus time (at mid-exposure) were obtained from the different observatories that recorded the occultation (Table 1). The black points and lines represent the light curves extracted from the observations. The blue lines show the best square-well-model fits to the main body and the ring at Konkoly, with square-well models derived from the assumed ring width and opacity (W = 70 km and p′ = 0.5) at other sites. The red points and lines correspond to the optimal synthetic profile deduced from the square-well model fitted at each data point (see Methods). The rectangular profile in green corresponds to the ring egress event at Skalnate Pleso, which fell in a readout time of the camera (see Fig. 3). The light curves have been shifted in steps of 1 vertically for better viewing. ‘Munich’ corresponds to the Bavarian Public Observatory. Error bars are 1σ.