MAXI J1659–152 is a rapidly spinning binary system comprising a black hole more than three times more massive than the Sun and a red dwarf companion star only 20% the mass of the Sun. The pair are separated by only 1.3 solar radii, or just under one million kilometres. Thanks to a 14.5 hour observing campaign by ESA’s XMM-Newton, scientists were able to measure a record-breaking orbital period of just 2.4 hours – the fastest spinning binary system with a black hole. The black hole orbits around the system’s common centre of mass at 150 000 km/h, while the companion travels at two million kilometres per hour, making it the fastest-moving star ever seen in a binary system.
The centre of mass is so close to the black hole due to its vast mass that it appears as if it is not orbiting. In this animation the focus is on the periodic absorption dips detected by XMM-Newton as the stream of material from the companion impacts on the black hole’s accretion disc.
The system was first found on 25 September 2010 by NASA’s Swift space telescope, with follow-up observations by the Japanese MAXI instrument on the International Space Station, NASA’s Rossi X-ray Timing Explorer, ESA’s XMM-Newton and ESO’s ground-based Very Large Telescope.