Magnetic fields spiral and slow the black hole's spin, releasing energy outward.
For fifty years, one of astrophysics' deepest riddles has haunted those who study the cosmos: how does a black hole, the universe's most absolute prison, manage to hurl energy across millions of light-years? Researchers at Princeton University now believe they have traced the answer to the invisible choreography of magnetic fields spiraling around M87*, the first black hole ever photographed, whose jets stretch ten times the length of our galaxy. The mechanism they describe is one of cosmic irony — a black hole's own rotation becomes the engine of its undoing, surrendering energy not into oblivion, but outward into the universe.
- A puzzle born in the late 1970s has grown more urgent as telescopes reveal jets of energy so vast they make entire galaxies look small — and no one could explain how something inescapable was letting anything escape.
- M87*, carrying the mass of 6.5 billion suns and sitting 53 million light-years away, has become the focal point of this crisis, offering astronomers their clearest window yet into the machinery of black hole behavior.
- The Princeton team used Event Horizon Telescope data to model how magnetic field lines from the surrounding accretion disk drag against the black hole's spin, siphoning rotational energy outward into the jets rather than inward into oblivion.
- The direction of the magnetic spiral turns out to be everything — reverse it, and the energy flows back into the black hole instead of being launched into space, suggesting black holes are far more behaviorally diverse than once assumed.
- The model fits observations remarkably well, but the team stops short of certainty, acknowledging that an unknown rotating plasma source cannot yet be ruled out — and that only next-generation telescopes may deliver the final proof.
For nearly half a century, astronomers have watched colossal jets of energy pour outward from black holes — structures stretching millions of light-years — and struggled to explain how something so gravitationally absolute could release anything at all. Now, a team at Princeton University believes they have finally mapped the mechanism behind this cosmic paradox, using the most studied black hole in existence as their laboratory.
M87*, the supermassive black hole at the heart of the Messier 87 galaxy, is an ideal subject. Carrying the mass of 6.5 billion suns and located 53 million light-years away, it became the first black hole ever directly photographed in 2019. Its jets — described by physicist Alexandru Lupsasca as "million-light-year-long Jedi lightsabers" releasing "truly insane" amounts of energy — extend roughly ten times the length of the Milky Way, making the mystery of their origin all the more pressing.
The answer, published in The Astrophysical Journal, lies in magnetic fields. Superheated plasma swirling in an accretion disk just outside M87*'s event horizon generates spiraling magnetic field lines that intersect the black hole itself. These fields create drag on the spinning black hole, and the rotational energy they bleed away is channeled outward into the jets. Crucially, the direction of the spiral determines the direction of the energy — reverse it, and the energy would be swallowed back rather than expelled.
Using computer models built from Event Horizon Telescope data, the team visualized this invisible machinery for the first time. The model aligns well with what observers see, but Lupsasca was careful to note that an alternative explanation — some unknown form of rotating plasma — cannot yet be fully dismissed. The findings also suggest that black holes are more behaviorally diverse than previously understood, with magnetic field orientation playing a decisive role in how each one behaves. The next generation of telescopes may finally close the case — but for now, the mystery has a compelling answer, if not yet a proven one.
For nearly half a century, astronomers have watched energy pour out of black holes in the form of colossal jets—structures so vast they dwarf entire galaxies—and wondered how it was possible. Nothing should escape a black hole's grip, yet here were these luminous torrents, stretching millions of light-years into space. Now, researchers at Princeton University believe they have finally mapped the mechanism that makes this cosmic escape act possible.
The black hole at the center of the Messier 87 galaxy, known as M87*, has become the laboratory for this investigation. Located 53 million light-years away, it carries the mass of 6.5 billion suns and has earned its place as one of the most scrutinized objects in astronomy. In 2019, it became the first black hole ever directly photographed. This year alone, scientists captured the first image of jets forming around it and measured its rotation for the first time by detecting a wobble in its spin. M87* is, in other words, the ideal subject for solving a puzzle that has eluded the field since the late 1970s.
The jets themselves are almost incomprehensibly large. They extend roughly ten times the length of the Milky Way, stretching across a million light-years of space. Alexandru Lupsasca, a former Princeton researcher now at Vanderbilt University and a recent winner of the New Horizon Prize in Physics, described them as "million-light-year-long Jedi lightsabers" that release what he called "truly insane" amounts of energy. Yet the fundamental question remained: how does a black hole, from which nothing should escape, manage to expel such staggering quantities of power?
The answer, according to the team's study published in The Astrophysical Journal on November 14, lies in the invisible architecture of magnetic fields. Around M87*, superheated plasma swirls in an accretion disk just outside the event horizon—the point of no return. This disk generates spiraling magnetic field lines that intersect the black hole itself. As these fields interact with the spinning black hole, they create drag that gradually slows its rotation. That rotational energy, rather than being lost, gets channeled outward into the jets. The direction the magnetic fields spiral determines which way the energy flows; reverse the spiral direction, and the energy would be pulled back into the black hole instead of ejected.
This mechanism had been theorized before, but the Princeton team did something new: they used computer models based on data from the Event Horizon Telescope to map exactly how these magnetic field lines twist and interact. For the first time, they could visualize the invisible machinery at work. Yet even as the model aligns remarkably well with observations of M87*'s jets, uncertainty remains. Lupsasca acknowledged that while it is "extremely likely the black hole powers the jet," the team cannot definitively rule out that some other source—perhaps an unknown form of rotating plasma—might be responsible instead.
The findings suggest that not all black holes lose energy the same way. The orientation of magnetic fields appears to be crucial. A black hole surrounded by oppositely spiraling fields would behave entirely differently, trapping energy rather than releasing it. This variability hints at a richer diversity in black hole behavior than previously understood. The team remains hopeful that the next generation of telescopes will provide the observational evidence needed to move this explanation from "extremely likely" to proven. For now, a mystery that has shadowed astrophysics for decades has a plausible answer—but the final word has not yet been written.
Citações Notáveis
These jets are basically like million-light-year-long Jedi lightsabers that release truly insane amounts of energy.— Alexandru Lupsasca, Vanderbilt University
It's extremely likely the black hole powers the jet, but we can't prove it yet.— Alexandru Lupsasca
A Conversa do Hearth Outra perspectiva sobre a história
Why does it matter how a black hole loses energy? Isn't the fact that it does enough?
Because understanding the mechanism tells us something fundamental about how the universe works at its most extreme. If we can't explain how energy escapes a black hole, we're missing a piece of the physics.
And M87* is special because it's been photographed?
Partly. But more importantly, we can actually see its jets and measure its spin. We have real data to test our theories against. Most black holes are too distant or too small to observe in this detail.
So the magnetic fields are doing the work of pushing energy out?
Yes. The fields spiral around the black hole and create friction—drag—that slows its rotation. That lost rotational energy has to go somewhere, and it goes into the jets.
But you said they can't prove it yet. What's missing?
They can't rule out other sources of energy. There could be plasma or other mechanisms we don't fully understand yet. The model fits the observations beautifully, but fitting isn't the same as proving.
What would proof look like?
Better telescopes. More detailed observations of the magnetic fields themselves, or measurements that would be impossible if any other mechanism were at work. The next generation of instruments might give us that clarity.
Does this apply to all black holes?
Not necessarily. The direction the magnetic fields spiral matters enormously. In another black hole, they might spiral the opposite way, and energy would be trapped instead of released. Every black hole might have its own story.