Washington: Astronomers have discovered the largest structure ever seen in space, which stretches 4 billion light-years across.
The structure is a large quasar group, a collection of gigantic galactic cores that is held together by a supermassive black hole, CBS News reported.
"While it is difficult to fathom the scale of this large quasar group (LQG), we can say quite definitely it is the largest structure ever seen in the entire universe," Roger Clowes , lead author of the study and a professor at the University of Central Lancashire in the U.K., said in a statement.
"This is hugely exciting, not least because it runs counter to our current understanding of the scale of the universe."
In comparison the Milky Way - measures roughly 100,000 light-years wide and the nearest galaxy, the Andromeda galaxy, is 2.5 million light-years away - less than one-thousandth of the width of the LQG.
Clowers and his team observed the gigantic structure via data that had been gathered by the Sloan Digital Sky Survey.
The discovery of the LQG runs counter to the prevailing theory that such massive objects should not exist. It would seem to violate the cosmological principle, the idea that the universe is more or less the same no matter when you are.
But the discovery of the massive LQG may call for a recalibrating of that theory.
"Our team has been looking at similar cases which add further weight to this challenge," Clowes said.
"And we will be continuing to investigate these fascinating phenomena," he said.
The study has been published in the Monthly Notices of the Royal Astronomical Society.