Ring of gamma ray bursts may be largest feature in the universe
A ring of nine cataclysmic explosions five billion light years across is thought to be the largest feature ever seen in the observable universe.
Each of the gamma ray bursts (GRBs) releases as much energy in a few seconds as the Sun will do over its 10 billion-year lifetime.
GRBs, the most luminous events in the universe, are thought to be the result of massive stars collapsing into black holes.
The ring is about seven billion light years from Earth and covers an area of sky more than 70 times the diameter of the full moon.
It challenges current theories about the make-up of the universe, which sets a theoretical limit of 1.2 billion light years for the largest structures.
Professor Lajos Balazs, from the Konkoly Observatory in Budapest, Hungary, who led the observations, said: "If we are right, this structure contradicts the current models of the universe. It was a huge surprise to find something this big - and we still don't quite understand how it came to exist at all."
The team now wants to establish whether known processes of galaxy formation and large-scale structure could have led to the ring's creation. If this proves not to be the case, astronomers will radically have to revise their theories about the evolution of the universe.
The research is published in the journal Monthly Notices of the Royal Astronomical Society.