Nasa scientists spot unusual set of rings around black hole with companion star

Astronomers have spotted a spectacular set of rings around a black hole in an image captured using Nasa’s Chandra X-ray Observatory and Neil Gehrels Swift Observatory. Nasa said that the X-ray images of the giant ring reveal information about the black hole, its companion star, and the intervening dust clouds.

“The black hole is part of a binary system called V404 Cygni, located about 7,800 light-years away from Earth. The black hole is actively pulling material away from a companion star — with about half the mass of the Sun — into a disk around the invisible object. This material glows in X-rays, so astronomers refer to these systems as “X-ray binaries,” the US space agency said.

In 2015, Neil Gehrels Swift Observatory discovered a burst of X-rays from V404 Cygni creating high energy rings. These rings were generated when a burst of X-rays from the black hole system bounced off of dust clouds between V404 Cygni and Earth, a phenomenon called light echoes. Cosmic dust consists of tiny, solid particles.

The rings tell astronomers about the landscape between V404 Cygni and Earth. According to Nasa, the diameter of the rings reveals the distances to the intervening dust clouds the light ricocheted off. When the cloud is closer to Earth, the high energy ring appears larger and vice versa.

“The light echoes appear as narrow rings rather than wide rings or haloes because the X-ray burst lasted only a relatively short period of time,” said Nasa.