By David Shiga
It looks like an empty patch of space, but astronomers say it holds a galaxy that contains no stars. If Robert Minchin of Cardiff University in Wales and his colleagues are right, they have found the first member of a population of galaxies that theorists have proposed but observers had never seen.
In 2000, Minchinâs team noticed two apparently isolated hydrogen clouds in a radio telescope survey of the Virgo Cluster of galaxies. Follow-up observations with visible-light telescopes showed that one of these clouds was associated with a faintly glowing galaxy. However, long exposures taken with the 2.5-meter, visible-light Isaac Newton Telescope in the Canary Islands offered up a surprise: The second cloud had no partner glowing galaxy.