Cosmic gas cloud blinks in sync with circling black hole

Scientists have detected a mysterious gamma-ray heartbeat coming from a cosmic gas cloud. The inconspicuous cloud in the constellation Aquila is beating with the rhythm of a neighbouring precessing black hole, indicating a connection between the two objects.

The system catalogued as SS 433 is located some 15,000 lightyears away in the Milky Way and consists of a giant star with about 30 times the mass of our sun and a black hole with about 10 to 20 solar masses. The two objects are orbiting each other with a period of 13 days, while the black hole sucks matter from the giant star.

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Two massive black holes are locked in a dance at the center of the OJ 287 galaxy. The larger black hole is surrounded by disk of gas; it is also orbited by a smaller black hole that collides with the disk, producing a flare brighter than 1 trillion stars. But because the system's complex physics affects the smaller black hole's orbit, the flares occur irregularly.

Scientists used NASA's Spitzer Space Telescope to detect one of these bright flashes on July 31, 2019, confirming that they can now anticipate the timing of these flares to within four hours using a detailed model of the system.

In the second half of the video, the animated diagram on the left illustrates the orbit of the smaller black hole (the red dot) around the larger black hole (the stationary white dot) and its collisions with the disk of gas (the pink line), which occur twice per orbit. The years of the collisions are indicated below the diagram and in the graphic on the right shows, dating to 1886.