The Laniakea Supercluster is a newly-recognized supercluster of galaxies, which includes the Milky Way Galaxy.
The Green Bank Telescope (GBT) in West Virginia was used to study the outer boundaries of the group of galaxies which encompasses our own family of stars. The smallest cluster, to which the Milky Way belongs, is called the Local Group, and includes 54 galaxies. The study also identified connections between other similar clusters throughout the Universe, which can connect the bodies in a gravitational embrace.
Superclusters of galaxies are the largest structures known to mankind. Together, the clusters can total hundreds of families of stars. They stretch across the Universe in filaments, resembling the outside of soap bubbles when viewed from great distances.
"We have finally established the contours that define the supercluster of galaxies we can call home. This is not unlike finding out for the first time that your hometown is actually part of much larger country that borders other nations," R. Brent Tully, astronomer at the University of Hawaii at Manoa, and lead researcher on the study, said.
The Laniakea Supercluster contains more than 100,000 galaxies, with a total mass of one hundred million billion suns. The massive grouping stretches 500 million light years from one side to another.
Renegade galaxies floating in the vast spaces between these superclusters are pulled by extreme gravitation exerted by the masses. By studying the movements of these galaxies, astronomers were able to precisely examine the large-scale structure of the massive structures.
The Milky Way galaxy is located near the edge of one supercluster. The outer boundary of this structure was carefully studied by examining the radial velocity of renegade galaxies. Gravity from each supercluster dominates a surrounding region of space and this new investigation examined the boundaries between each territory.
The Great Attractor is a gravitational anomaly in the Hydra-Centaurus Supercluster. Nothing can be seen there, but the region exerts a gravitational force tens of thousands of times greater than the Milky Way galaxy. This force affects the motion of the Milky Way, along with the rest of the Local Group and other clusters. Until now, astronomers were uncertain as to the nature of the mysterious effect. Galaxies within the Local Group are collapsing inward, toward a gravitational valley. Astronomers who recognized this supercluster identifies the Great Attractor as a gravitational well, affecting galaxies across the massive galactic group.
Laniakea is a Hawaiian word meaning "immense heaven."
Discovery of the Laniakea supercluster was detailed in the journal Nature.
