Ok, I think we’re on the same page here. But I’m still not sure about one of your previous comments, you suggested that this “heaviest object” can’t move because it would be the logical reference to which any other body is measured.

But I want to think about that a bit. Let’s say this heaviest object (HO) has something orbiting it and we’re looking at it from earth with a telescope. As the smaller body orbits, we would probably see this HO wobble, right? Meaning that even if it’s the most massive thing around, it’s still affected by other objects, it can be moved.