Eighteen billions times more massive than our Sun is what the enormous black hole OJ287 weighs; six times more than the largest measured until now. This massive object is actually orbited by a smaller black hole which is fortunate as it allowed researchers to test Einstein’s theory of gravity as affected by the strong gravitational field. The existence of the smaller black hole also enabled the accurate measurement of the larger black hole’s mass. These findings were just announced at the 211th meeting of the American Astronomical Society in Austin, Texas.

Schematic of OJ287 system (Turku University)

Only 3.5 billion light-years away in the constellation Cancer, the dual black holes generate a pulsing light signal of significant size twice every twelve years. A quasar is powered by gas falling into a large black hole and as a result releasing energy in the form of a pulse. From this quasar, predictive models confirmed the pulses suggesting the binary black hole system. The pulses were observed as predicted in September and October of last year. Scientists believe that as the smaller black hole revolves around the larger black hole, its tears through a disc of matter surrounding the larger one twice, which releases the energy detected as a pulse.

Mauri Valtonen of Tuorta Observatory in Finland presented the findings in Austin. The largest telescopes involved in the study were the German funded Calar Alto telecope in Almeria, Spain and the Nordic optical telescope.