"Dark Galaxy" Identified by Hubble

NASA's Hubble Space Telescope has revealed an exceptional discovery in the Perseus galaxy cluster: CDG-2, an ultra-low surface brightness galaxy composed of 99% dark matter.

This elusive galaxy remained hidden until astronomers detected a slight increase in globular cluster density, suggesting the presence of an underlying galactic structure. Observations from Hubble, ESA's Euclid observatory, and the Subaru Telescope confirmed a faint halo of diffuse light surrounding these ancient star clusters.

Analysis indicates CDG-2 has the luminosity of approximately six million Sun-like stars, with the clusters comprising about 16% of its visible matter. The galaxy's normal matter was likely stripped away through gravitational interactions within the Perseus cluster.

This discovery provides a rare opportunity to study dark matter's fundamental properties and how it shapes galactic evolution across the universe.

For more information, visit science.nasa.gov/mission/hubble

Credit: NASA's Goddard Space Flight Center
Paul Morris: Lead Producer

Video Credits:
A simulation of the formation of dark matter structures from the early universe until today.
Ralf Kaehler/SLAC National Accelerator Laboratory, American Museum of Natural History


Image of the Subaru Telescope: NAOJ via ESA

Music Credit:
"Lost to Eternity" by Timothy James Cornick [PRS] via BBC Production Music [PRS] and Universal Production Music