A team led by Cosimo Inserra reports the first direct observation of a spacetime "whirlpool" around a spinning black hole. By tracking radio and X-ray emissions from the tidal disruption event AT2020afhd, astronomers found the accretion disk and jets wobbling together — a signature of Lense–Thirring precession. The finding, published in Science Advances, offers strong, multiwavelength evidence that a black hole can drag spacetime around it.
Astronomers Detect First Direct 'Whirlpool' in Spacetime Around a Spinning Black Hole
An artist's impression of star wobbling around black hole. Credit NASA.
Einstein’s general theory of relativity predicts many counterintuitive effects. Astronomers now report the first direct observation of one of the most striking: a whirlpool-like twisting of spacetime produced by a rapidly rotating black hole.
Occasionally a star drifts too close to a black hole and is torn apart by extreme tidal forces in a process called a tidal disruption event (TDE). The shredded stellar material forms an accretion disk around the black hole, while powerful jets of matter can blast outward — a chaotic and energetic scene visible across the electromagnetic spectrum.
The Discovery
By monitoring radio and X-ray emissions from one such event, designated AT2020afhd, researchers found that signals from both the accretion disk and the jets were oscillating together. The coordinated wobble indicates the black hole’s spin is dragging the surrounding spacetime and forcing the disk and jet to precess in unison — effectively creating a vortex in spacetime.
“Our study provides the most compelling evidence yet of Lense–Thirring precession — a black hole dragging spacetime along with it much like a spinning top stirring water into a whirlpool,” said Cosimo Inserra of Cardiff University, a lead author on the paper.
What It Means
This effect, known as Lense–Thirring precession and first predicted by Josef Lense and Hans Thirring more than a century ago, had remained observationally elusive until now. The new multiwavelength observations — combining radio and X-ray monitoring — provide a clear signature that the black hole’s rotation is influencing the motion of nearby matter and light.
The results, published in Science Advances, add a powerful new observational confirmation of general relativity in the strong-gravity regime and demonstrate how coordinated, long-term monitoring across wavelengths can reveal subtle relativistic phenomena around black holes.
Why It Matters: Detecting Lense–Thirring precession outside our Solar System helps astronomers probe black hole spin, accretion physics, and jet formation. It also shows that surprising relativistic effects predicted long ago can now be seen directly with modern telescopes.
Credit: Science Advances; research led by Cosimo Inserra, Cardiff University.
