Scientists have identified what they believe is the largest feature in the observable universe.
A team of researchers spotted a ring of nine gamma ray bursts and galaxies that is a whopping five billion light-years across, the Royal Astronomical Society reported. Gamma-ray bursts (GRBs) are the universe's brightest objects, and are the products of massive stars collapsing into black holes. The GRBs' brightness helps researchers find elusive galaxies in the distant universe.
A team of researchers used a number of ground-based observatories to observe the ring, which appears as more than 70 times the diameter of the Full Moon in the sky. The researchers believe there is only a one in 20,000 probability of the GRBs being in this distribution.
Current models of the universe suggest the structure of the cosmos is uniform on the largest scales. The model, dubbed the "Cosmological Principle," has been backed up by observations of the early universe through the cosmic microwave background, but this new discovery challenges the principle. The widespread model sets a theoretical limit of 1.2 billion light years for the largest structures, and this newly discovered feature is five times larger than the proposed limit.
"If the ring represents a real spatial structure, then it has to be seen nearly face-on because of the small variations of GRB distances around the object's center. The ring could though instead be a projection of a sphere, where the GRBs all occurred within a 250 million year period, a short timescale compared with the age of the universe," said Lajos Balazs of Konkoly Observatory.
A spheroidal ring projection should mirror the strings of clusters of galaxies surrounding voids in the universe, but the massive ring ten times larger than any known voids.
"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," Balazs said.
The findings were published in a recent edition of the journal Monthly Notices of the Royal Astronomical Society.