Researchers studying the aftermath of a gigantic black hole collision may have confirmed a gravitational phenomenon predicted by Albert Einstein A century ago.
According to new research published today (October 12) in the journal Nature (opens in a new tab)the phenomenon, which is known as precession and is similar to the wobbling motion sometimes seen in a spinning top, occurred when two ancient black holes they collided and merged into one. As the two massive objects rotated closer together, they released huge ripples through the fabric of space-time known as gravitational waves, which surged through the cosmos, pulling energy and angular momentum away from the merging black holes.
Scientists first detected these waves emanating from black holes in 2020, using the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and the Virgo gravitational-wave sensors in Italy. Now, after years of studying wave patterns, researchers have confirmed that one of the black holes was spinning wildly, to a degree never seen before.
The spinning black hole was twisting and spinning 10 billion times faster than any previously observed black hole, warping both space and time so much that it caused both black holes to wobble, or precede, in their orbits.
Researchers have observed precession in everything from the top of the spindle to dying star systems, but never in objects as huge as binary black hole systems, in which the two cosmic vacuum cleaners orbit around a common center. However, Einstein’s general theory relativity predicted more than 100 years ago that precession should occur in objects as large as binary black holes. Now, the study authors say, this rare phenomenon has been observed in nature for the first time.
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“We’ve always thought that binary black holes can do this,” study lead author Mark Hannam, director of the Institute for Gravity Exploration at Cardiff University in the United Kingdom, said in a statement. “We were hoping to find an example from the first gravitational wave detections. We had to wait five years and more than 80 separate detections, but finally we have one!”
The black holes in question were many times more massive than Sun, with the larger of the two estimated to be around 40 solar masses. Researchers first learned about the binary pair in 2020, when LIGO and Virgo detected a burst of gravitational waves released by the two black holes’ supposed collision. The team named this collision GW200129, after the date of its discovery (January 29, 2020).
Since then, other scientists have pored over the initial gravitational-wave data, uncovering increasingly bizarre secrets about this epic collision. (Although scientists only have gravitational waves to go on and no direct observations, they cannot determine the precise location of the black holes.)
For example, in May 2022, a team of researchers calculated that the merger between the two black holes was massive and uneven, according to the Live Science sister site. space.comwith gravitational waves coming off the collision in one direction, while the newly merged black hole was probably “blasted” out of its home galaxy at more than 4.8 million km/h (3 million mph) in the opposite direction.
This new research in Nature suggests that the two black holes had a chaotic relationship before their violent merger. As the two gigantic objects pulled each other into closer and closer orbit, they began to wobble like drunken tops, precessing several times a second. According to the study’s authors, this precession effect is estimated to be 10 billion times faster than any other that has ever been measured.
These findings vindicate Einstein, who predicted that such effects were possible in some of the largest objects in the universe. But the results also raise the question of whether black hole mergers like this are as rare as once thought.
“The largest black hole in this binary, which was about 40 times more massive than the Sun, was spinning about as fast as physically possible,” said study co-author Charlie Hoy, a Cardiff University researcher at the time of the study. . and now at the University of Portsmouth in the UK. “Our current models of how binaries form suggest this was extremely rare, maybe one in a thousand. Or it could be a sign that our models need to change.”