The First Black Hole We Ever Saw Is Doing Something It Has Never Done Before: Its Magnetic Field Flips
Images from the Event Horizon Telescope across 2017, 2018, and 2021 reveal a dramatic change in the magnetic field around M87*, even as the black hole itself remains essentially unchanged. Between 2017 and 2021, the magnetic field direction flipped completely—the first time such a change has been seen around a black hole. This cosmic weather could help scientists understand how these giants feed and how their jets are powered as they shoot across intergalactic space.
In This Article:
A Giant in Our Cosmic Backyard: The 6.5-Billion-Solar-Mass Black Hole 55 Million Light-Years Away
M87* is a supermassive black hole in a galaxy 55 million light-years away, with a mass around 6.5 billion solar masses. As the first subject of the Event Horizon collaboration's mission to image a supermassive black hole, M87* has become one of the most studied objects in the universe. Since the release of the first iconic image in 2019, the collaboration has continued to observe M87*, collecting data across years to track changes in the hot material roiling near the edge and to study where jets originate. “Jets like the one in M87 play a key role in shaping the evolution of their host galaxies,” says astronomer Eduardo Ros of the Max Planck Institute for Radio Astronomy in Germany. “By regulating star formation and distributing energy across vast distances, they affect the life cycle of matter on cosmic scales.”
Time-Lapse of a Black Hole's Magnetic Weather
The team focused on the polarization of light: as light travels through a strongly magnetized environment, the orientation of its waves can become organized and aligned. In 2017, the magnetic fields appeared to spiral clockwise; by 2018, they shifted anticlockwise and appeared to stabilize; by 2021, they appeared to spiral anticlockwise again. These results suggest that the magnetic fields around M87* change significantly, and on very short cosmic timescales, while the black hole itself remains the same. “What's remarkable is that while the ring size has remained consistent over the years—confirming the black hole's shadow predicted by Einstein's theory—the polarization pattern changes significantly,” says astronomer Paul Tiede of the Harvard & Smithsonian Center for Astrophysics. This tells us that the magnetized plasma swirling near the event horizon is far from static; it's dynamic and complex, pushing our theoretical models to the limit.
Why This Matters: How Magnetic Fields Shape Jets and Galaxy Evolution
Magnetic fields are thought to play a key role in creating jets by guiding material along field lines to the poles. As jets pour out at near-light speeds, they regulate star formation and distribute energy across intergalactic distances, shaping the evolution of their host galaxies. The polarization mapping provides scientists with a new tool to test theories about how black holes feed and how jets are launched. Remo Tilanus of the University of Arizona's Steward Observatory says, “Pioneering a new frontier in time-domain black hole astrophysics, the Event Horizon Telescope is planning an ambitious series of rapid-fire observations across March and April 2026.” We are excited to be gearing up to capture the first movie of M87*, something that has been on our wish list ever since that first image of a black hole.
The Next Act: The Movie of M87* and What We Hope to Learn
Future observations in 2026 will be a rapid-fire series designed to produce the first movie of M87*. Time-domain black hole astrophysics could reveal how the magnetized environment evolves in real time and help test theories about how jets are launched. The research was published in Astronomy & Astrophysics. In the long run, these insights will help us understand how supermassive black holes feed their galaxies and drive cosmic evolution.
