Great Attractor
An aggregation of galaxies, containing perhaps 5 × 1016 solar masses of matter, roughly 150-350 million light years from our Galaxy in the direction of the constellations Hydra and occultation. Measurements of the velocities of galaxies, out to about 300 million light years, show deviations of up to 500 km/s from the pure Hubble flow, and our Galaxy also moves relative to the cosmic background radiation. The gravitational pull of the Great Attractor is thought to be partly responsible for these motions.