Not all astronomers agree the results are such a surprise.
The new paper is one of several in the past two years that have "discovered" the wild galaxies.
Scott Chapman at the University of Cambridge's Institute of Astronomy in the United Kingdom published his own sightings of such galaxies in 2005.
He said the current paper "really does not offer anything new to the speculation."
George Rieke, at the University of Arizona in Tucson, led NASA's Spitzer Space Telescope team for 15 years. He declined to comment on the paper.
"I think praising the new work would get me in trouble with those who did the older effort," he said.
Nevertheless, the new galaxies further open a stunning new window into the skies, many experts agree. (Learn about galaxy hunters.)
You Can't Believe Your Eyes
Wilson said it took so long to see these galaxies partly because of human bias.
"Our eyes are adapted to optical light and that's how we built our telescopes," he said.
But dust hides most of the starlight in the bright galaxies, and optical telescopes aimed straight toward them—even the Hubble Space Telescope—see only darkness.
The Spitzer Space Telescope can see the galaxies because it uses infrared wavelengths, though it gets interference from other galaxies.
A newer breed of telescope, called submillimeter telescopes, uses wavelengths between the infrared and radio wavelengths.
The James Clerk Maxwell Telescope in Hawaii, which originally spotted the new galaxies, will soon be fitted with a new submillimeter camera.
The device will allow it to detect hundreds to thousands of hot, distant galaxies every year.
And the Large Millimeter Telescope, under construction now in Mexico, will open the door to discovering hundreds of such galaxies per hour, rather than hundreds per decade, Wilson of the University of Massachusetts said.
The galaxies provide countless opportunities to study new stars.
Scientists still don't really know how stars form or how starbursts happen, Wilson said, but now all those processes may come into focus.
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