Quote Originally Posted by Vyk View Post
True

What I don't get is when you have two stars together, they get one name and call it a binary star. So I don't understand why when you have two planets in partnership (pluto/charon) it wasn't called a binary planet
It is being called that. Anyway, the classification for such things depends on where the center of mass around which the bodies orbit is. If it is outside both bodies, it is a binary system. If it inside one of the bodies, it is a planet/moon system.