Illustration of the binary system (IMAGE) University of Turku Caption Artistic illustration of OJ287 as a binary black hole system. The secondary black hole of 150 million solar masses moves around the primary black hole of 18 billion solar masses. A disk of gas surrounds the latter. The secondary black hole is forced to impact on the accretion disk twice during its 12-year orbit. The impact produces a blue flash which was detected in February 2022. In addition, the impact also induces the secondary black hole to bright bursts of radiation several weeks earlier, and these bursts have also been detected as a direct signal from the secondary black hole. Credit AAS 2018 Usage Restrictions Please credit the image to AAS 2018. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.