Although the first black hole ever imaged by mankind greatly expanded our horizons, whether these black holes were spinning or not and their motions remained unclear. Today, there has been an important development on this subject.
An international team of scientists led by Chinese researcher Dr. Cui Yuzhu analyzed 22 years of observational data collected by more than 20 telescopes around the world.
They found that the black hole at the center of the M87 galaxy, which is 6.5 billion times larger than our Sun, exhibits a motion that oscillates up and down every 11 years. This phenomenon confirms that black holes do indeed spin.
Black holes swallow huge amounts of gas and dust with their enormous gravity. A small portion of these particles that do not fall into the black hole are ejected and appear as narrow rays along the axis, moving at a speed close to the speed of light. These rays are called “jets”. Telescope observations show that M87’s jet oscillates 10 degrees in a repeating 11-year cycle, as predicted by Einstein’s General Theory of Relativity.
So What Causes M87’s Jet To Oscillate Back And Forth?
The researchers’ analysis shows that the black hole’s spin axis is not perfectly aligned. This disk-like structure is typically found around a black hole because it is composed of material that gradually spirals into the vacuum to be consumed.
This misalignment between the rotating mass and the matter spinning around it causes a “significant effect on the surrounding spacetime” that affects the motion of nearby objects in what the General Theory of Relativity calls “frame dragging”.
Scientists have yet to find out how fast M87 is spinning, which requires further observations and analysis.