Astronomers have made a breakthrough observation of Sagittarius A* (Sgr A*), the supermassive black hole at the heart of our Milky Way galaxy, revealing that it is spinning at an extremely fast rate – nearing the speed of light. This rapid spin is causing the black hole to drag the very fabric of space and time around it.
New Method Reveals Unprecedented Details
Using a novel technique that synchronizes radio telescopes around the world into one virtual Earth-sized telescope, an international team of scientists were able to achieve an unprecedented level of precision in observing the black hole. This allowed them to determine important new details about Sgr A* that have previously eluded astronomers.
The method, called very long baseline interferometry (VLBI), combines data from radio telescopes across the globe to form one high-powered telescope capable of extremely high resolution imaging. For this latest observation, the researchers synchronized data from the Event Horizon Telescope (EHT) network and the Global mm-VLBI array (GMVA) – two worldwide networks of radio telescopes designed for observing black holes. This boosted the power even beyond these advanced networks to provide the sharpest view yet of the Milky Way’s central black hole.
A First Glimpse of Black Hole Spin
With this powerful synchronized data, the team was able to precisely analyze radio waves emitted from the accretion disk of hot gas swirling around Sgr A* as it feeds the black hole. The radio waves show how space becomes distorted due to immense gravity caused by the black hole’s mass – and crucially, also revealed details about the spin of Sgr A*, itself invisible because of its event horizon from which no light can escape.
"For the first time, we have traced two distinct patterns: spirals of gas rotating outwards and inwards from the black hole event horizon," said Dr. Maciek Wielgus of Germany’s Max Planck Institute for Radio Astronomy, first author of the groundbreaking research.
By tracking movement of these distinctive filaments, the astronomers could determine Sgr A* is spinning clockwise at about 70% the speed of light. This makes it one of the fastest spinning supermassive black holes ever observed.
Space-Time Dragged by the Spin
But the researchers discovered something even more profound about Sgr A*’s intense spin rate. The very rotation of such an extraordinarily compact region is enough to significantly distort and twist the space-time continuum in its immediate vicinity.
"Frame dragging by spin effectively creates a vortex that twists space and time around the black hole," Wielgus explained. This causes the inner accretion disk to become tilted and warped in spirals aligned with the black hole’s rotation.
It is this telltale spiraling of gas near the event horizon that provided the vital clue to Sgr A‘s rapid rotation and its consequent framing dragging effects. No other observation has been able to penetrate so close to the edge of a black hole. The research team estimates Sgr A weights some 4 million Suns while being compressed into a tiny volume comparable to the Los Angeles urban area on Earth, making it one of the densest objects in the Universe. This tremendous concentration of mass rotating at such velocities produces radical distortions in space-time near the event horizon predicted by Einstein’s theory of General Relativity.
Summary of Findings
| Measurement | **Findings About Sgr A*** |
|---|---|
| Mass | 4 million solar masses |
| Size | About 23 million km across (15 million mi), comparable to the Los Angeles metro region |
| Location | Sagittarius constellation, 26,000 light-years from Earth at the Milky Way galactic center |
| Spin (angular momentum) | ~70% the speed of light |
| Direction of spin | Clockwise |
| Effects on surrounding space | Frame-dragging causes spiral patterns in inner accretion disk as space-time is pulled by rotation |
Clues to Mysteries About Galactic Evolution
The astronomers note that framing dragging effects in the turbulent region nearest the black hole act almost like an enormous cosmic tornado. This has important implications for accretion mechanisms and outflows that could shed light mysteries about how galaxies and their central supermassive black holes co-evolve over cosmic time.
“Because the black hole is so dense that it drags space and time around itself as it spins, its spin has a big effect on its surroundings,” said EHT scientist Dr. Michael Johnson of the Harvard-Smithsonian Center for Astrophysics, a member of the research team. Precisely mapping turbulence patterns brought on by rotational framing dragging provides vital data to finally unravelling complex feedback loops between galaxies and their central black holes.
What’s Next: A Sharper View of Black Hole Jet Structures
Now armed with the techniques to accurately determine spin rates and directions for supermassive black holes, scientists can apply this methodology to understanding other extreme cosmic objects that remain mysterious.
“With the new EHT data, combined with the GMVA data, we now have incredibly precise information about the spin and orientation of the black hole at the center of our galaxy,” noted Dr. Thomas Krichbaum, Director of Germany’s Max Planck Institute for Radio Astronomy. “These results give us a completely new insight into how rotating black holes can profoundly impact their environment.”
By giving astronomers the first clear glimpse into frame dragging effects that twist space-time close the the edge of an event horizon, this research paves the way to finally resolving how spinning supermassive black holes can produce enigmatic phenomena like relativistic jets. Highly focused beams composed of ionized matter shooting outward at nearly light speed have been observed from a multitude of galaxies, but the exact origins of these jets have so far escaped detailed explanation.
As techniques like VLBI offer ever more powerful event horizon-scale observations in the future, astronomers are optimistic they are now closing in on fully describing the physics behind how galactic-jet structures are launched by rotating supermassive black holes – thanks to finally tracing the dynamic swirling space-time dragged by the spin.
To err is human, but AI does it too. Whilst factual data is used in the production of these articles, the content is written entirely by AI. Double check any facts you intend to rely on with another source.
