Scientists had suspected for years that this galaxy contained two black holes, but they did not have powerful enough telescopes to distinguish them from each other. Now, a research team from the University of Turku in Finland has been able to provide the first direct evidence of the existence of a pair of black holes.

To achieve this achievement, scientists combined ground antennas and a satellite located halfway to the moon, forming a virtual radio telescope with a size equivalent to 15 times the diameter of the Earth. This enabled them to obtain an image with 100,000 times greater resolution than any previous means of observing OJ287.

explains Professor Mauri Valtonen, lead researcher From the University of Turku, Finland: “For the first time, we were able to obtain an image of two black holes orbiting each other.”

The OJ287 galaxy belongs to the class of quasars, which are extremely bright galactic nuclei with massive black holes at their centre. Although the black hole itself does not emit light, the gas and dust falling toward it are heated to extremely high temperatures, producing huge amounts of radiation that can be monitored by astronomical observatories.

This quasar has a unique character, as its light oscillates according to a regular pattern that is repeated every 12 years. Professor Mauri Valtonen explains that this phenomenon is due to the presence of two black holes orbiting each other in a 12-year orbit, which explains the clear periodic pattern of change in the intensity of light emanating from the galaxy.

To capture a clearer picture of this complex cosmic system, scientists used Very Long Baseline Interferometry (VLBI) technology, which allows signals from radio telescopes spread across Earth and space to be combined to form a giant virtual telescope. Using the RadioAstron satellite, the team was able to capture the first accurate radio image of the quasar OJ287, opening the door to a deeper understanding of the phenomena of double black holes in the universe.

The image revealed that one of the two black holes is enormously larger than the other, as the mass of the larger one is about 18.35 billion times the mass of the sun, while the mass of the smaller one does not exceed 150 million solar masses. The smaller black hole rotates in a volatile orbit around its giant companion, colliding with the dense accretion disk surrounding it every revolution due to the enormous force of gravity.

Scientists observed a unique behavior of the energy streams emanating from the smaller black hole, as they noticed that they swayed and twisted randomly, similar to what happens to a firehose in which water is strongly rushing. They called this phenomenon the “flapping tail,” likening it to a tail vibrating violently in space.

Researchers believe that this unusual behavior is due to the enormous orbital speed of the smaller black hole around its larger partner, which leads to the deflection of energy streams and their constant change in direction. Scientists expect to witness, in the coming years, clear changes in the movement of this “cosmic tail” with a change in the path and speed of rotation in the unique dual system.

These important results were published in the Astrophysical Journal.