The cosmos has once again revealed its mysteries, providing a significant breakthrough for scientists hunting one of the universe’s most elusive phenomena. A study published today in Science Advances details the first-ever observations of a swirling vortex in spacetime, a spectacle caused by a rapidly rotating black hole.
This phenomenon, known as Lense-Thirring precession or frame-dragging, describes how black holes twist the spacetime around them, affecting the orbits of nearby stars. The team, led by the National Astronomical Observatories at the Chinese Academy of Sciences and supported by Cardiff University, focused on AT2020afhd, a tidal disruption event (TDE) where a star was torn apart by a supermassive black hole.
Unveiling the Mysteries of Black Holes
During this cosmic event, a swirling disk formed around the black hole from the remnants of the star, ejecting powerful jets of matter at nearly the speed of light. The researchers observed rhythmic changes in both X-ray and radio signals, noting that the disk and jet wobbled in unison every 20 days.
First theorized by Albert Einstein in 1913 and mathematically defined by Lense and Thirring in 1918, this observation confirms a prediction of general relativity, opening new avenues for studying black hole spin, accretion physics, and jet formation.
Expert Insights and Implications
Dr. Cosimo Inserra, a Reader in the School of Physics and Astronomy at Cardiff University and co-author of the paper, remarked, “Our study shows the most compelling evidence yet of Lense-Thirring precession – a black hole dragging spacetime along with it in much the same way that a spinning top might drag the water around it in a whirlpool.”
“This is a real gift for physicists as we confirm predictions made more than a century ago. Not only that, but these observations also tell us more about the nature of TDEs – when a star is shredded by the immense gravitational forces exerted by a black hole.”
Unlike previous TDEs, which exhibited steady radio signals, AT2020afhd’s signals showed short-term changes, further confirming the dragging effect and providing scientists a new method for probing black holes.
Technological Advances in Space Observation
The team modeled X-ray data from the Neil Gehrels Swift Observatory (Swift) and radio signal data from the Karl G. Jansky Very Large Array (VLA) to identify the frame-dragging effect. Further analysis using electromagnetic spectroscopy allowed them to describe and identify the process.
“By showing that a black hole can drag spacetime and create this frame-dragging effect, we are also beginning to understand the mechanics of the process,” explains Dr. Inserra. “So, in the same way a charged object creates a magnetic field when it rotates, we’re seeing how a massive spinning object – in this case, a black hole – generates a gravitomagnetic field that influences the motion of stars and other cosmic objects nearby.”
Looking to the Future
This discovery not only confirms a century-old theory but also enhances our understanding of the universe. It serves as a reminder of the extraordinary phenomena that exist beyond our planet, waiting to be discovered.
“It’s a reminder to us, especially during the festive season as we gaze up at the night sky in wonder, that we have within our grasp the opportunity to identify ever more extraordinary objects in all the variations and flavors that nature has produced,” Dr. Inserra reflects.
The paper, titled ‘Detection of disk–jet coprecession in a tidal disruption event,’ is now available in Science Advances, marking a significant milestone in astrophysical research and our understanding of black holes.
