A black hole’s corona vanished completely, then reformed—something never seen before in astronomy.
Key Takeaways:
- Astronomers witnessed a black hole’s corona vanish and then rebuild itself for the first time.
- The disappearance caused the black hole’s brightness to drop by a factor of 10,000 in a year.
- Scientists suspect a star plunged into the black hole, disrupting its magnetic field and corona.
- Observations from telescopes like NASA’s NICER captured this event in real time.
- This discovery offers new insights into how black hole coronas form and are powered.
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For the first time, astronomers have observed a supermassive black hole’s corona completely disappear and then reappear. This extraordinary event was tracked by MIT and other institutions using multiple telescopes, revealing an unprecedented transformation in a black hole’s high-energy environment.
A Sudden and Extreme Disappearance
The discovery began in March 2018 when the All-Sky Automated Survey for Supernovae (ASSASN) detected an unexpected burst of brightness from 1ES 1927+654, an active galactic nucleus (AGN) located about 100 million light-years away. The object, which had been relatively unremarkable, suddenly became 40 times brighter than usual.
Following this outburst, astronomers observed something extraordinary: the corona—an ultrabright, billion-degree ring of high-energy particles surrounding the black hole—vanished entirely. This resulted in a dramatic drop in brightness by a factor of 10,000 within a year, with some fluctuations occurring in just hours. Normally, such changes in brightness take thousands to millions of years.
The leading theory suggests that a star was pulled into the black hole’s gravity, disrupting its swirling accretion disk. This disturbance likely caused the high-energy corona particles to plummet into the black hole, making the corona disappear.
The Corona Rebuilds Itself
After the disappearance, astronomers continued to monitor the black hole using telescopes like NASA’s NICER, an X-ray detector aboard the International Space Station. In just a few months, they observed the black hole pulling material back into its accretion disk, gradually restoring the corona. While not yet at its original luminosity, the corona continues to emit high-energy X-rays, suggesting that the system is still recovering.
This research, published in Astrophysical Journal Letters, provides crucial insights into how black hole coronas form and behave. Scientists now believe that the corona’s existence is linked to magnetic fields within a specific radius around the black hole. This event has given astronomers a rare opportunity to study black hole physics in real time, and they will continue monitoring 1ES 1927+654 to see if it undergoes more unexpected transformations.
