Models of: (top left) H_v magnitude; (top right) optical light curve amplitude and; (bottom left) apparent diameter of Chiron for a 114 × 98 × 62 km Jacobi ellipsoid with p_v = 0.10 and the orientation proposed by Ortiz et al. (2015). The modeled H_v and apparent diameter are calculated at a phase corresponding to mean light curve brightness. The first two panels include the effect of rings with a 20% I/F reflectivity. In the top right panel, the blue symbols are the measurements as collected by Groussin et al. (2004), augmented by more recent measurements by Ortiz et al. (2015) and Galiazzo et al. (2016). In the bottom left panel, the model is compared to values of the diameter derived from our modeling of past thermal infrared observations (see Groussin et al. 2004). In the bottom right panel, the black points show ratios of individual measured thermal fluxes (some are shifted by ±0.1 yr for better visibility) by the elliptical NEATM model. In this panel, the green points (shifted by +1 in yr) show the ratio of ring-corrected thermal fluxes by fluxes calculated from the elliptical model (see text for details).