ESA Science & Technology - Artist's impression of black hole

This artist's impression shows hot gas orbiting in a disc around a rapidly-spinning black hole. The elongated spot depicts an X-ray-bright region in the disc, which allows the spin of the black hole to be estimated.

Studying the black hole devouring a star known as ASASSN-14li with ESA's XMM-Newton space observatory and NASA's Chandra and Swift X-ray observatories, a team of astronomers has discovered an exceptionally bright and stable signal that allowed them to determine the black hole's spin rate.