Eridanus is caused by a hole in the universe nearly
one billion light-years across.
The universe has a huge hole in it that dwarfs anything else of its kind. The discovery caught astronomers by surprise.
The hole is nearly a billion light-years across. It is not a black hole, which is a small sphere of densely packed matter. Rather, this one is mostly devoid of stars, gas and other normal matter, and it's also strangely empty of the mysterious "dark matter" that permeates the cosmos. Other space voids have been found before, but nothing on this scale.
Astronomers don't know why the hole is there.
"Not only has no one ever found a void this big, but we never even expected to find one this size," said researcher Lawrence Rudnick of the University of Minnesota.
Rudnick's colleague Liliya R. Williams also had not anticipated this finding.
"What we've found is not normal, based on either observational studies or on computer simulations of the large-scale evolution of the universe," said Williams, also of the University of Minnesota.
The finding will be detailed in the Astrophysical Journal.Full story at Space.com
also at Astronomy.com