If there were no massive objects these things would go flying off, or at least go at a much slower rate because all that determines how they go around is how much mass is inside its orbit.
만약 거기에 거대한 질량이 존재하지 않는다면 항성은 날아가버리거나 좀 더 천천히 공전을 하겠죠. 왜냐하면 어떻게 공전하는가를 결정하는건 궤도안에 있는 질량이기 때문입니다.