Left panel: variation of the H_V during time. Data taken from Belskaya et al. (2010) and our own observations. The solid curve represents the model described by Eq. (1). It is fitted to the data, assuming the ring pole position mentioned in the text (λ = 138, β = 28). We assume that Chariklo’s rotation axis is aligned with ring pole. The grey line is the model assuming the other, wrong, pole position. The right panel shows the variation of the aspect angle with time (orange line, scale at right). As can be seen, the aspect angle is 90° in the period 2007−2008. The variation of the area ratio (blue line, scale at left) is also presented in this panel. Vertical lines are the dates when reflectance spectra were taken. The area of Chariklo was considered to be the one of an ellipsoid with axis a = 122 km, b = 122 km, and c = 117 km. The area of the rings were calculated with the parameters taken from Braga-Ribas et al. (2014).