Scientists find clump of black holes inside the heart of globular cluster (video)
By Mike Wall 17 hours ago
Such clusters could be important gravitational-wave sources.
The globular cluster NGC 6397, as imaged by NASA's Hubble Space Telescope.
(Image: © NASA, ESA, T. Brown, S. Casertano, and J. Anderson (STScI))
A tight knot of stars nearly as old as the universe hides a dark secret at its core.
The globular cluster NGC 6397, a conglomeration of stars about 7,800 light-years from Earth, likely harbors a clump of small black holes at its heart, a new study reports.
Researchers studied the movement of stars in NGC 6397 using NASA's Hubble Space Telescope and the European Space Agency's Gaia spacecraft. These motions revealed the existence of a hidden mass at the cluster's center — a "central dark component" that makes up 0.8 to 2% of NGC 6397's total mass.
That inferred mass is consistent with an intermediate black hole, a cosmic beast midway between stellar-mass black holes, which form after the collapse of big stars, and the supermassive beasts that sit at the cores of most, if not all, galaxies.
More:
https://www.space.com/black-holes-globular-cluster-hubble-telescope?utm_source=notification