The rings in this image surround a black hole that is part of a binary system called V404 Cygni. Located about 7,800 light years away from Earth, the black hole is sucking material away from a companion star. The material in the rings glows in x-rays, so astronomers refer to such systems as “x-ray binaries.” The x-ray images of the rings were captured by the Chandra X-ray Observatory and the Neil Gehrels Swift Observatory. (I designed some of the assemblies in the power and thermal control systems for one of the instruments on Swift.)
X-ray: NASA / CXC / U.Wisc-Madison / S. Heinz et al.
Optical / IR: Pan-STARR
On June 15, the Swift satellite caught the onset of a rare X-ray outburst from a stellar-mass black hole in the binary system V404 Cygni. In that system a stream of gas from a star much like the sun flows toward a 10 solar mass black hole. Instead of spiraling into the black hole, the gas accumulates in an accretion disk around it. Every couple of decades, the disk changes state, sending the gas rushing inward. The result is a new X-ray outburst.
V404 Cygni is a binary system that contains an erupting black hole. These rings of x-ray light centered on that system were imaged by the x-ray telescope aboard the Swift satellite. Color indicates the energy of the X-rays, with red representing the lowest (800 to 1,500 electron volts, eV), green for medium (1,500 to 2,500 eV), and blue for the most energetic (2,500 to 5,000 eV). Visible light has energies ranging from about 2 to 3 eV. The dark lines running diagonally through the image are artifacts of the imaging system.
Image Credits: Andrew Beardmore (Univ. of Leicester) and NASA