Astronomers discover the biggest thing in the Universe

There's some pretty big stuff out there in the Universe,
but how big is the biggest? According to a team of
Hungarian-US scientists led by Prof Lajos Balazs, the
largest regular formation in the Universe is a ring of nine
galaxies 7 billion light years away and 5 billion light
years wide. Though not visible from Earth, the newly
discovered feature covers a third of our sky.
The ring was revealed by nine Gamma-Ray Bursts (GRB)
originating from the nine galaxies. GRBs are the
brightest, most energetic events in the cosmos, putting
out as much energy in seconds as the Sun will in its
entire lifetime. They're caused by supernovae or
hypernovae – supermassive stars collapse into neutron
stars or black holes in times ranging from milliseconds
to a few hours. Aside from their spectacular deaths, they
also help astronomers to measure the distance of other
galaxies.
In this case, the observed GRB's indicate that the nine
galaxies are positioned in a ring shaped like a shell.
They also show that the galaxies are all of a very similar
distance from Earth – according to Prof Balazs, there's
only a 1 in 20,000 chance that the ring's arrangement is
accidental.
If it was visible to us, the ring would cover 36 percent of
the sky, making it 70 times bigger than a full moon.
The importance of the ring isn't just that it appears to
be a record breaker – it raises questions about the
architecture of the Universe. In particular, it casts
doubts on the Cosmological Principle. First asserted by
Sir Isaac Newton and developed based on observations
of the cosmic microwave background radiation and the
structure of the early universe in the past century, it
states that at the largest scale, the Universe is uniform,
so no matter where you are, it looks essentially the
same.
According to the team, recent work indicates that the
largest structures can't be more than 1.2 billion light
years across. This is at odds with the new discovery, as
the ring is about five times as big, implying a much
more uneven cosmos.
The next step for the team is to see if the processes
controlling galaxy formation and large scale structure
could have produced the ring without violating the
Cosmological Principle. If not, it could require rethinking
how the Universe evolved.
"If we are right, this structure contradicts the current
models of the universe," says Balazs. "It was a huge
surprise to find something this big – and we still don’t
quite understand how it came to exist at all."