科学美国人60秒:Milky Way's Home Supercluster Found

We finally know our cosmic address. For the first time, astronomers have identified our home supercluster—a conglomeration of groups of galaxies and larger clusters of galaxies, all interconnected in a stringy web.

Researchers, led by an astronomer at the University of Hawaii at Manoa, have named this supercluster Laniakea, which means “immense heaven” in Hawaiian. Laniakea encompasses 100,000 galaxies stretched out over 500 million light-years. Our own Milky Way is just one of these. The study is in the journal Nature. [Brent Tully et al, The Laniakea supercluster of galaxies]

Superclusters are some of the universe’s largest structures, and have boundaries that are tough to define—especially from inside one. The team used radio telescopes to map out the motions of a large collection of local galaxies.

Within a given supercluster, all galaxy motions will be directed inward, toward the center of mass. In the case of Laniakea, this gravitational focal point is called the Great Attractor, and influences the motions of our Local Group of galaxies and all others throughout our supercluster. It’s time to update our intergalactic maps: Laniakea is home sweet home.

—Clara Moskowitz