In gray, Charon ephemerides positions (DE421+plu021) relative to Pluto for right ascension (left) and declination (right). In black, the corresponding photocenter correction presents the expected periodic behavior, but not in the same scale or function form. The dispersions in the plots for a given relative distance are due to the rotation of the apparent orbit of Charon projected in the sky, during the 19 years of our observations.