A British-led team of astronomers have discovered the first galaxy completely devoid of stars. The galaxy (which is a large mass, about 50 million light years away) can only be detected using a radio telescope. First captured by the University of Manchester’s Lovell Telescope in Cheshire, the discovery was also confirmed by the Arecibo telescope in Puerto Rico.

Dark Galaxy, Invisible (Courtesy: PhysOrg)The galaxy (named VIRGOHI21) is mostly composed of hydrogen, and is about a hundred million times the mass of the Sun, lying in the Virgo cluster. Such galaxies have been predicted before (and might outnumber the visible galaxies by 100 to 1), but this is the first time anyone has 'seen' one.
It is theorized that since galaxies rotate at a fairly fast pace (our own Milky Way complete one rotation in about 250 million years), dark matter is necessary to ensure that the galaxies do not tear themselves apart. Detecting such dark matter hitherto has been elusive. The techniques that led to the discovery of this dark galaxy can undoubtedly be used to detect other dark matter clumps in our own galaxy, and beyond.