In 2019, the first ever picture of a black hole taken by the Event Horizon Telescope was released. The EHT is a collaboration of about a dozen observatories from around the world. Researchers have continued adding new telescopes to the project, including one on Kitt Peak National Observatory near Tucson.
New findings in the journal Astronomy and Astrophysics show that the magnetic field flipped around the black Hole M87* in 3 different images from 2017, 2018 and 2021.
Study co-author Boris Georgiev is a postdoctoral researcher with the University of Arizona's Steward Observatory. He said the key was looking at how the polarization of light evolved from year to year, similar to when you put on polarized sunglasses and tilt your head.
"It's a changing environment. These aren't some systems that just you look at every year and they look the same and there's no process. No, there's large changes in either material that's coming in or material surrounding it," Georgiev said.
Georgiev said there are changes every few hours, which is very fast on cosmic scales where changes in structures can take billions of years.
The black hole is about 24 billion miles across. To compare, the orbit of Neptune is about 3.5 billion miles in diameter. It takes Neptune about 165 years to orbit our Sun. The matter surrounding the black hole, which orbits even farther away than the event horizon, can orbit in about a week.
Georgiev said that next year the Event Horizon Telescope will be continuously observing M87* to get a better understanding of what causes those changes.
