Abstract
It is believed that Pluto-Charon is in a double (1:1) synchrounism. It is a very particular system: Pluto eccentricity (0.2) is similar to Mercury’s one, however they have different obliquities: Pluto s obliquity varies in the range 103 to 128 degrees, while Mercury s obliquity is constant, almost zero. Differently from some authors, we will take Andoyer variables, in 3D space. Besides, w…