Astronomers have discovered evidence of galaxies in a region of the universe previously believed to be vacant of all matter, it was reported Thursday.

Greg Bothun, an astronomer at the University of Michigan in Ann Arbor, said he and his colleagues detected infrared energy believed to signify the presence of galaxies in the constellation Bootes, which is located about 500 million light years from Earth."We found evidence that the void is probably not as big as previously thought," said Bothun in a telephone interview before he was to present his findings at a meeting of the American Astronomical Society in Boston.

"There are more galaxies there than we might have expected based on prior data, Bothun said.

The astronomers discovered the galaxies using data obtained by the Infrared Astronomical Satellite (IRAS), which was launched in 1983 by NASA.

The scientists compared the amount of infrared energy detected in the area of the void to another randomly selected region of the sky and found them to be roughly equivalent.

The infrared energy is emitted by dust that would be heated up by stars in the area if galaxies were present, Bothun said.

"When we looked at the Bootes void region and counted the number of infrared sources and looked at a comparison area," Bothun said, "we found the two fields had roughly the same source counts, which is hard to understand if one of the fields isn't supposed to have any galaxies."

He said the findings suggest that the size of the void is smaller than previously believed.