Top: upper panel, data (solid) and best fit (dashed line) for 18022636-2555373. The lower panel shows, displaced by arbitrary offsets and enlarged for clarity, the residuals of the fits by a point-like (above) and by a binary star model including corrections due to slope variations (see text). The normalized χ² values are 4.42 and 1.46, respectively. The times of the geometrical occultation of two stars are also marked, with their difference corresponding to a separation of 9.9 mas. Bottom: brightness profile reconstructed by the model-independent CAL method.