<< an international team of astronomers has found a massive galaxy that consists almost entirely of dark matter. The galaxy, Dragonfly 44, is located in the nearby Coma constellation and had been overlooked until last year because of its unusual composition: It is a diffuse “blob” about the size of the Milky Way, but with far fewer stars >>
<< Dragonfly 44’s mass is estimated to be 1 trillion times the mass of the Sun, or 2 tredecillion kilograms (a 2 followed by 42 zeros), which is similar to the mass of the Milky Way. However, only one-hundredth of 1% of that is in the form of stars and “normal” matter. The other 99.99% is in the form of dark matter — a hypothesized material that remains unseen but may make up more than 90% of the universe >>
Jim Shelton. Scientists discover a ‘dark’ Milky Way. August 25, 2016
Pieter van Dokkum , Roberto Abraham, et al. A high stellar velocity dispersion and ~100 globular clusters for the ultra- diffuse galaxy dragonfly 44. ApJ 828 L6 Published 2016 August 25.