Supermassive black holes locked in a stable orbit around each other

Summary

Researchers have released the first confirmed image of two black holes orbiting each other. The observation confirms a theory that has remained unproven for more than 40 years. The discovery centres on quasar OJ287, located five billion light-years from Earth in the constellation Cancer. Quasars are the luminous cores of distant galaxies, powered by the gravitational energy of supermassive black holes. The image shows two bright points, each representing a jet of high-energy particles emitted by one of the black holes. The black holes themselves remain invisible, but the image provides clear visual evidence of their position, motion, and dual existence. The larger of the two has a mass estimated at 18 billion times that of the Sun. The smaller is around 150 million times the Sun’s mass. The team behind the discovery used radio data collected a decade ago by the RadioAstron satellite, whose antenna extended to nearly halfway between Earth and the Moon. This allowed for an image resolution roughly 100,000 times higher than that achieved by Earth-based telescopes. Mauri Valtonen, an astronomer at the University of Turku and lead author of the study published in the Astrophysical Journal, said the image marks the first direct evidence of a binary black hole system. “For the first time, we managed to get an image of two black holes circling each other. The black holes are identified by the intense particle jets they emit,” he said. The existence of two black holes in OJ287 was first suggested in 1982. Aimo Sillanpää, then a graduate student at the University of Turku, observed that the brightness of the quasar changed regularly over a 12-year cycle. The pattern implied that two massive objects were orbiting each other and affecting the quasar’s brightness as they passed through surrounding matter. For decades, scientists monitored the object using various observational tools, including the NASA TESS satellite, which captured visible light from both black holes. However, ...