This new photo of a supermassive black hole is unlike any before, showing powerful magnetic fields spiraling around it
- A new photo of the supermassive black hole at our galaxy's core looks different from those before.
- A groundbreaking collaboration of black-hole-imaging scientists published it on Wednesday.
The supermassive black hole at the heart of our galaxy has a side you've never seen before.
A new image shows powerful magnetic fields swirling around our hometown black hole called Sagittarius A*, pronounced "A-star."
The image is the latest innovation of a groundbreaking scientific collaboration called the Event Horizon Telescope, or EHT, which rallied telescopes across the planet to focus on one black hole together, effectively creating an observatory as big as Earth.
Five years ago, the EHT released the first-ever photo of a supermassive black hole, a feat thought to be impossible for decades because black holes are objects so dense that not even light can escape them, making them invisible.
But the disc of ultra-hot material circling a black hole, which you can see in the image below of a supermassive black hole at the center of a galaxy called Messier 87, is visible.
Not long after that, Sagittarius A* got its moment in the limelight.
Sagittarius A*'s 2022 portrait, below, looked quite similar to Messier 87's, even though Sagittarius A* is about 1,000 times smaller than Messier 87's black hole.
But the new image released on Wednesday is different. It shows our galaxy's black hole in polarized light, which occurs when light waves oscillate in a preferred direction.
The new view below reveals a clear polarization pattern in the particles circling the black hole — which means powerful magnetic fields spiraling around the edge of Sagittarius A* affect them.
"What we're seeing now is that there are strong, twisted, and organized magnetic fields near the black hole at the center of the Milky Way galaxy," Sara Issaoun, an astrophysicist at the Harvard and Smithsonian Center for Astrophysics and the co-lead of the project, said in a press release.
A clue about the secret structure of supermassive black holes
Sagittarius A* is about 27,000 light-years away from Earth, so this image represents a very tiny point in the sky.
"This appears the same size in the sky as a donut on the moon," Issaoun said at a press conference presenting the first image of it in 2022.
But the discovery of the magnetic-field lines offers a major clue about the behavior of supermassive black holes across the universe and how they eat the material surrounding them.
The EHT had previously imaged its first black hole, Messier 87, in polarized light, though it doesn't look quite as striking.
Since both black holes have similar magnetic-field structures despite their immense size difference, the EHT scientists now suspect that all supermassive black holes might have magnetic structures like this.
"We've learned that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them," Issaoun said.
The discovery also suggests that, like Messier 87, Sagittarius A* could have a jet of radiation and high-speed particles shooting out of the black hole. We just can't see it yet.
The telescope observations that led to this new image took place in 2017, but the EHT is poised to cast its gaze at Sagittarius A* again in April.
Issaoun and her collaborators published their findings in two papers in The Astrophysical Journal Letters on Wednesday.
Bigger black-hole breakthroughs may be in store
Further imaging with new innovative techniques and technologies could reveal even more secrets of supermassive black holes, both big and small.
The EHT aims to capture video of our galaxy's black hole, possibly by the end of the decade, Michael Johnson, an astrophysicist on the project, told Business Insider at a meeting of the American Astronomical Society in January.
"We think we're just scratching the surface of what can be done," Johnson said in a presentation at that meeting. "Even more exciting science is yet to come."
To that end, the EHT recently added a telescope in Greenland to its worldwide array.
Incorporating satellites into that array, thereby expanding the EHT observatory into space, could allow scientists to study dozens of black holes instead of just two. Johnson said that's likely to happen within a decade.