Teams at SUNY-Stony Brook and the National Astronomical Observatory of Japan have discovered 854 dark galaxies with the use of archival data from the Subaru Telescope. The findings are key in figuring out the history and process of star formation, stretching back billions of years ago.

For the uninitiated, a dark galaxy is comprised almost entirely of dark matter, and 1 percent or less of visible matter. Galaxies like these are created when there is a loss or diffusion of gas. Typically, dark galaxies are more or less invisible: they contain little to no visible stars, and cannot generate new stars due to low gas density, hence the name.

In a press statement released June 22 by the National Astronomical Observatory of Japan, principal investigator Jin Koda commented, "Not only these galaxies appear very diffuse, but they are very likely enveloped by something very massive." His observations point to the general theory behind the creation of dark galaxies: namely, that gas is siphoned out of them by a gravitational pull.

"Follow-up spectroscopic observations in the future may reveal the history of star formation in these dark galaxies," said Koda, which in turn might help scientists figure out the origin of model galaxy formation, including the blueprints of the Milky Way itself.

Dark galaxies are first thought to have been discovered back in 2012.