Chords in the plane of the sky corresponding to the three sites that obtained observations (shown with the black straight lines), with the moments corresponding to the extinction events indicated with the same numeric labels as in the light curves. The segment for Wise observatory is shorter than that of Kottamia because the image acquisition process started later than planned. The black ellipse corresponds to the nominal ring proposed in Ortiz et al. (2015), which requires some changes to be consistent with the extinction features 1 and 4. The dotted lines show the axes of the ellipse. The motion of the star is from right to left. A better model for the ring is shown in Fig. 4.