A re-examination of the region, discovered by U.S. astronomer Lawrence Rudnick and colleagues at the University of Minnesota, has found the "void" might have been a statistical artifact.

Rudnick found a cold spot in the cosmic microwave background measured by a U.S. satellite. Using the National Radio Astronomy Observatory's Very Large Array telescope, he concluded the cold spot coincided with a void nearly 1 billion light-years across -- the largest ever seen.

But a new analysis casts doubt on Rudnick's conclusions.

The existence of voids is really a matter of interpretation, astronomer Kendrick Smith at the University of Cambridge told New Scientist magazine. He said his work with Dragan Huterer of the University of Michigan suggests Rudnick's findings were incorrect.

Because there are always stars in front of it and behind it, a void cannot be seen with the naked eye, so it must be inferred statistically. Smith and Huterer raise doubts about Rudnick's statistics and said they plan to submit their findings to the Royal Astronomical Society.