A Galaxy Devoid of Dark Matter

Right: A closer look at one of the globular clusters within the galaxy, which are all much brighter than typical, the brightest emitting almost as much light as the brightest within the Milky Way. The spectrum, obtained by Keck Observatory shows the absorption lines used to determine the velocity of this object. Ten clusters were observed, providing the information needed to determine the mass of the galaxy, revealing its lack of dark matter.

Astronomers using data from the Gemini and W. M. Keck Observatories in Hawai‘i have encountered a galaxy that appears to have almost no dark matter. Since the Universe is dominated by dark matter, and it is the foundation upon which galaxies are built, “...this is a game changer,” according to Principal Investigator Pieter van Dokkum of Yale University.

“Finding a galaxy without dark matter is unexpected because this invisible, mysterious substance is the most dominant aspect of any galaxy,” said van Dokkum. The research is published in the March 29^th issue of the journal Nature and the Gemini press release can be found here.