Invisible matter slowing star movement may be devoured by black holes.

Scientists may have discovered indirect evidence that large amounts of invisible dark matter surround black holes, which could represent a major breakthrough in dark matter research. The team used stars orbiting black holes in binary systems as proxies and found that the slow-down of the stars' orbits was the result of dark matter surrounding the black holes, generating significant friction and a drag on the stars. The team's results help to confirm a long-held theory in cosmology that black holes can swallow dark matter that comes close enough to them, creating a "density spike" in their immediate vicinity that can subtly influence the orbit of surrounding objects.