Astronomers report CDG‑2, about 300 million light‑years away in the Perseus Cluster, appears to be ~99.9% dark matter and is visible only through a few bright globular star clusters and a faint halo. The team used Hubble, ESA's Euclid, and Subaru data plus a globular‑cluster–based search method to infer a massive dark halo with almost no ongoing star formation, likely because a cluster environment stripped its gas.
— If confirmed, these nearly starless 'dark' galaxies become clean laboratories to test dark matter behavior and galaxy‑formation theory and provide a new observational route (globular clusters) to find more such objects.
Ethan Siegel
2026.04.21
80% relevant
Both this article and the existing idea concern empirical evidence for dark matter as the best explanation for anomalous gravitational effects; the Big Think piece reports a new observational test that strengthens the case for dark matter over modified gravity (MOND), directly connecting to prior reporting about unusually dark‑matter‑dominated systems.
EditorDavid
2026.03.07
100% relevant
Lead author Dayi Li’s study using Hubble, Euclid, and Subaru data identified four globular clusters and a faint halo in the Perseus Cluster consistent with a massive dark‑matter halo that lacks stars.
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