Washington, 23 February (HS): Astronomers from the National Aeronautics and Space Administration (NASA) have identified a faint “ghost galaxy” composed predominantly of dark matter with the help of the Hubble Space Telescope.

According to details shared by NASA, the low-surface-brightness galaxy, designated CDG-2, is estimated to be made up of nearly 99 per cent dark matter. The discovery was made using advanced statistical techniques that helped scientists detect small clusters of stars known as globular clusters within the otherwise nearly invisible galaxy.

Located approximately 300 million light-years away in the Perseus galaxy cluster, CDG-2 is so faint that it cannot be observed through normal stellar brightness. Instead, researchers identified it through four dense globular clusters embedded within it.

NASA stated that while most galaxies are visible due to the light emitted by billions of stars, certain galaxies are extremely dim and difficult to detect. These are classified as low-surface-brightness galaxies. Such systems contain relatively few stars, with the majority of their mass believed to consist of dark matter — a form of matter that neither emits, reflects nor absorbs light.

Preliminary measurements suggest that the total luminosity of CDG-2 is equivalent to about six million Sun-like stars, which is significantly lower than that of a typical galaxy. The findings have been published in The Astrophysical Journal Letters.

NASA noted that the Hubble Space Telescope’s flight operations control centre is located at the Goddard Space Flight Center in Greenbelt, Maryland, where teams of engineers, scientists and flight controllers monitor the telescope’s operations around the clock.

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Hindusthan Samachar / Jun Sarkar