The Great Attractor is an observed gravitational attraction in intergalactic space that is pulling thousands of galaxies toward it, including the Milky Way. A group of astromomers in 1986 were observing the motions of the Milky Way and neighbouring galaxies. Through a series of velocity tests, they noticed that the galaxies were moving toward the Hydra-Centaurus superclusters with velocities vastly different than what was predicted by the expansion of the universe. It was named by Alan Dressler in 1987, an American astronomer at the Carnegie Institution for Science of Washington. Even though it was officially named and located in 1987, there has been the first indications reported in 1973 of abnormalities. They saw that neighboring galaxies were being pulled off course at around a million miles per hour towards a force, being the Great Attractor.
Despite this, we are most likely never going to reach the Great Attractor due to the expansion of the universe. It is so huge that the Laniakea isn't gravitationally bound, in the way that galaxies and galaxy groups are. Even if we travelled at the speed of light(approx 670,616,629 mph), it would still take 220 million years to reach the Great Attractor.
Astronomers in 2005 conducted an X-ray survey in the Clusters in the Zone of Avoidance (CIZA). They found out that the Great Attractor was only one tenth the mass that scientists had originally thought it was. It is suggested to have a mass of 1016 solar masses, but it is obscured by the Milky Way's galactic plane, behind the Zone of Avoidance (ZOA). This makes it difficult to observe in visible light wavelengths directly. The Great Attractor is not dense enough to be gravitationally bound, so instead of it dispersing as the universe expands, it is held by a gravitational focal point. This means that it would be the core of Laniakea Supercluster.
