For the first time, astrophysicists have measured the recoil — or "kick," in the parlance — resulting from the birth of a new black hole that formed from the merger of two preexisting ones.

The international team of researchers measured the ripples in the fabric of spacetime, known as gravitational waves, allowing them to get unprecedented insights into the turbulent dynamics of two black holes crashing into each other.

The team analyzed data collected by the Advanced LIGO and Virgo gravitational wave detectors in 2019 that appears to record two black holes merging, with the resulting larger one being kicked away at thousands of miles per second.

The event, dubbed GW190412, saw a black hole eight times the Sun's mass colliding with another black hole that was 30 times the mass of the Sun, some 2.4 billion light-years away.

The team observed uneven gravitational waves scattering in different directions, as detailed in a new paper published in the journal Nature Astronomy last week. But the mix of signals will vary significantly, depending on where the observer is located with respect to the black hole recoil.

"Black-hole mergers can be understood as a superposition of different signals, just like the music of an orchestra consistent with the combination of music played by many different instruments," said lead author and University of Santiago de Compostela professor Juan Calderon-Bustillo in a statement. "However, this orchestra is special: audiences located in different positions around it will record different combinations of instruments, which allows them to understand where exactly they are around it."

Calderon-Bustillo and his colleagues determined that the resulting black hole was accelerated to a blistering 31 miles per second, which is technically enough to leave a cluster of gravity-bound stars. However, whether the event took place in such a cluster remains unknown, as ScienceAlert points out, given the extreme distances involved.

The team also measured in what direction the resulting black hole recoiled, as observed from the Earth, and the system's orbital angular momentum.

The research could allow scientists to study other black hole mergers using both gravitational waves in addition to electromagnetic signals.

"Black-hole mergers in dense environments can lead to detectable electromagnetic signals — known as flares — as the remnant black hole traverses a dense environment like an active galactic nucleus," explained coauthor and Chinese University of Hong Kong PhD student Samson Leong in the statement.

In short, it's an impressively detailed recreation of a violent event a billion light-years away.

"This is one of the few phenomena in astrophysics where we're not just detecting something — we're reconstructing the full 3D motion of an object that's billions of light-years away, using only ripples in spacetime," said coauthor and Pennsylvania State University astrophysicist Koustav Chandra in the statement.

"It’s a remarkable demonstration of what gravitational waves can do," he added.

More on black hole mergers: Scientists Detect Sign of Something Impossible Out in Deep Space


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