“Discounting cosmic expansion, their map shows flow lines down which galaxies creep under the effect of gravity in their local region…Based on this, the team defines the edge of a supercluster as the boundary at which these flow lines diverge. On one side of the line, galaxies flow towards one gravitational centre; beyond it, they flow towards another. ‘It’s like water dividing at a watershed, where it flows either to the left or right of a height of land,’ says Tully.”
Using an algorithm based on the velocity of redshifting galaxies, a team of University of Hawaii astronomers identify our galaxy’s place in the newly-identified Laniakea supercluster. (Laniakea being Hawaiian for “Immeasurable Heaven.”) Adds Slate‘s Phil Plait: “Laniakea is about 500 million light years across, a staggering size, and contains the mass of 100 quadrillion Suns — 100 million billion times the mass of our star.”
