This image shows six of the three-dozen "ultraviolet luminous galaxies" spotted in our corner of the universe by NASA's Galaxy Evolution Explorer. These massive galaxies greatly resemble newborn galaxies that were common in the early universe. The discovery came as a surprise, because astronomers had thought that the universe's "birth-rate" had declined, and that massive galaxies were no longer forming.
The galaxies, located in the center of each panel, were discovered after the Galaxy Evolution Explorer scanned a large portion of the sky with its highly sensitive ultraviolet-light detectors. Because young stars pack most of their light into ultraviolet wavelengths, young galaxies appear to the Galaxy Evolution Explorer like diamonds in a field of stones. Astronomers mined for these rare "gems" before, but missed them because they weren't able to examine a large enough slice of the sky. The Galaxy Evolution Explorer surveyed thousands of nearby galaxies before finding three-dozen newborns.
While still relatively close in astronomical terms, these galaxies are far enough away to appear small to the Galaxy Evolution Explorer. Clockwise beginning from the upper left, they are called: GALEX_J232539.24+004507.1, GALEX_J231812.98-004126.1, GALEX_J015028.39+130858.5, GALEX_J021348.52+125951.3, GALEX_J143417.15+020742.5, GALEX_J020354.02-092452.5.
Image credit: NASA/JPL-Caltech/Johns Hopkins