Batygin deduces the conditions under which a disk will warp in response or, conversely, will behave like a rigid body held fast by its own mutual gravity. (scientificamerican.com)
This is called a binary star and they are held together by their mutual gravity and orbit in a path around each other. (sciencedaily.com)
But too small a bomb would cause the fragments to fly apart only slowly, allowing them to clump together under their mutual gravity. (newscientist.com)