Great Attractor

Proposed concentration of mass, equivalent to tens of thousands of galaxies, that influences the movement of many galaxies, including the Milky Way Galaxy (see galaxy). In 1986 a group of astronomers noted that the Milky Way and neighbouring galaxies exhibit systematic deflections from the motion predicted by Edwin P. Hubble's theory of the expanding universe. One possible explanation is a large collection of galaxies exerting a gravitational pull on the clusters of galaxies around it; its centre would lie in the direction of the constellations Hydra or Centaurus in the southern sky, about 200 million light-years from Earth.

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