Based on multi-year data from the Event Horizon Telescope (EHT), the finding reveals a dynamic and unstable region just outside M87*’s event horizon. While the black hole’s shadow has remained unchanged, the surrounding magnetized plasma has undergone dramatic shifts, offering new clues about how black holes interact with their surroundings.
Located about 55 million light-years away, M87* is a supermassive black hole in the Virgo galaxy cluster. With a mass roughly 6.5 billion times that of the Sun, it became the first black hole ever imaged, when its now-iconic silhouette was published in 2019 by the EHT collaboration. Since then, it has become one of the most studied objects in astrophysics.
A Complete Magnetic Field Flip Around the Black Hole
While standard images of M87* appear consistent over time, scientists have been analyzing the polarization of light coming from the black hole’s surroundings. When light moves through a strongly magnetized environment, the orientation of its waves becomes aligned, revealing patterns invisible in traditional imaging.
According to ScienceAlert, polarization data from 2017 showed the magnetic field swirling in a clockwise direction. By 2018, the pattern had shifted anti-clockwise, and by 2021, it had fully stabilized in that new orientation. This is the first time a magnetic polarity flip has been detected around any black hole.
“This tells us that the magnetized plasma swirling near the event horizon is far from static,” said Paul Tiede of the Harvard & Smithsonian Center for Astrophysics, “it’s dynamic and complex, pushing our theoretical models to the limit.”
Connection to the Powerful Jets From M87*
M87* is also known for its relativistic jets—massive beams of material that shoot out from the black hole’s poles at speeds close to that of light. These jets play a major role in shaping the evolution of their host galaxies. As stated by Eduardo Ros from the Max Planck Institute for Radioastronomy, they “regulate star formation and distribute energy across vast distances.”
Magnetic fields are believed to be central to how these jets are formed. As hot material spirals around the black hole in an accretion disk, some of it escapes instead of falling in. Theoretical models suggest that magnetic field lines help guide this matter to the poles, where it’s launched outward into intergalactic space.
By tracking the polarization changes, scientists hope to understand the exact role of magnetic structures in this extreme jet-launching process. The reversal seen in the magnetic field indicates that the plasma near the event horizon is in constant motion, and possibly far more volatile than previously assumed.
Preparing for Future Real-Time Observations
This discovery marks a shift toward time-domain black hole astronomy, where researchers study how black holes evolve across time. The EHT team now plans a new wave of observations to capture these changes in greater detail.
According to Remo Tilanus of the University of Arizona’s Steward Observatory, an ambitious observation campaign is scheduled for March and April 2026, aiming to record a “movie” of M87*. This series of rapid-fire images will allow scientists to watch the magnetic field and plasma activity evolve in real time.
