Dark Matter Galaxy Confirmed in the Perseus Cluster

Astronomers report a faint galaxy about 300 million light‑years away whose mass is estimated at roughly 99.94–99.98 percent dark matter. The object, tentatively named CDG-2, was detected through four globular clusters and faint residual light seen when combining Hubble, Euclid and Subaru data.

A faint galaxy dominated by dark matter has been reported in the Perseus cluster. It lies about 300 million light‑years from Earth and is tentatively named CDG-2. Only four globular clusters were bright enough to be seen individually for years. A study in The Astrophysical Journal Letters reports that combined Hubble, Euclid and Subaru data reveal a faint glow linking those clusters to an underlying galaxy. Key points: - Location: about 300 million light‑years away in the Perseus cluster. - Detection: four globular clusters previously thought to be separate are reported as parts of the same galaxy. - Observations: combined Hubble, Euclid and Subaru data show a faint residual glow around the clusters. - Luminosity: total light equivalent to roughly 6 million suns, with the four clusters contributing about 16 percent. - Dark matter fraction: authors estimate 99.94–99.98 percent of the galaxy's mass is dark matter. - Publication: the analysis is reported in The Astrophysical Journal Letters under the tentative name CDG-2. Summary: This reported system is an unusually dark example of a galaxy and may serve as a natural case for testing models of dark matter and galaxy formation. Undetermined at this time.