Astronomers have captured the first radio image of two supermassive black holes orbiting each other. These black holes are located in a system called OJ287, which is between 3.5 and 5 billion light-years from Earth. One black hole is very large, about 18 billion times the mass of our sun. The other is smaller, with a mass of 150 million suns. Every twelve years, the smaller black hole passes through the larger one's disk of gas and dust, causing bright eruptions of light.
For a long time, scientists believed this pair existed, and now they have proof. An international team used a special method to create the image. They combined ground-based radio telescopes with the Russian RadioAstron space telescope. Because RadioAstron was far from Earth, the combined telescopes acted like one giant camera, much sharper than regular telescopes.
Black holes cannot be seen directly because they trap all light. However, this new image shows them by revealing the streams of energetic particles they shoot into space. Mauri Valtonen, a lead researcher, explained that the image shows the black holes through their particle jets.
The image also shows a detail about the smaller black hole: its jet forms a spiral shape as it moves quickly around the larger one. Scientists expect this shape to change in the future. The study of OJ287 has been going on for many years, with astronomers noticing its brightness changes since the 1800s. The system is a type of object called a blazar, meaning its radiation points towards Earth. The discovery confirms the existence of orbiting supermassive black holes, ending a long scientific debate.