Many galaxies are gravitationally bound together to form clusters, which themselves are loosely bound into superclusters, which in turn are sometimes seen to align over even larger scale structures.

• 许多星系由于引力作用而被束缚在一起形成星团，有些相对松散形成了超星系团，而有些星系一起组成队列形成更大规模的结构。