NASA’s Hubble Identifies One of Darkest Known Galaxies

Summary
The elusive object dubbed CDG-2 may be composed of 99% dark matter.
Most galaxies in the nearby universe are quite luminous. But some are so faint they’re nearly invisible. Astronomers, using the Hubble Space Telescope in combination with other observatories, identified a galaxy that appears to be almost entirely dominated by dark matter with only a smattering of stars. The galaxy, known as Candidate Dark Galaxy-2 (CDG-2), appears to contain just four globular star clusters (compared to the Milky Way’s 150-plus), and dimly shines with the light of only about 6 million Suns.
Full Article
In the vast tapestry of the universe, most galaxies shine brightly across cosmic time and space. Yet a rare class of galaxies remains nearly invisible — low-surface-brightness galaxies dominated by dark matter and containing only a sparse scattering of faint stars. One such elusive object, dubbed CDG-2, may be among the most heavily dark matter-dominated galaxies ever discovered. (Dark matter is an invisible form of matter that does not reflect, emit, or absorb light.) The science paper detailing this finding was published in The Astrophysical Journal Letters. Detecting such faint galaxies ...Visit NASA Science to view the full news release including article text and associated Hubble imagery, graphics, scientific visualizations, videos, captions, text descriptions, and other information.
News releases highlighting the discoveries of NASA’s Hubble Space Telescope are produced for NASA by the Space Telescope Science Institute (STScI) in Baltimore, Maryland, under NASA Contract NAS5-26555. News release content is developed by the News Team in STScI’s Office of Public Outreach.
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