Chinese astronomers have discovered a new galaxy FAST J0139+4328 using the FAST radio telescope. The newly discovered galaxy is isolated, has a relatively small stellar mass, and is dominated by dark matter. The discovery is reported in an article published on the arXiv preprint server.

The discovery was the result of an analysis of data from the FAST HI survey, as well as data from the Pan-STARRS system. The team has discovered several new clouds of neutral atomic hydrogen in the local universe, including an isolated cloud designated FAST J0139+4328.

Further study of FAST J0139+4328 showed that this is a typical disk galaxy with an extremely low absolute magnitude. The stellar mass is estimated at 690,000 solar masses, and the mass of neutral atomic hydrogen is estimated at 83 million solar masses. The ratio of dynamical mass to total baryonic mass for FAST J0139+4328 is approximately 47±27, which indicates that dark matter dominates ordinary matter in this galaxy.

The discovery represents the first time that a gas-rich, isolated dark galaxy has been discovered in a neighboring universe, which is at the earliest stage of galactic formation.