We have an update on the Event Horizon Telescope’s observations of the supermassive black hole in the core M87. 

In 2019, an amazing image of the glowing material and bent light twisting around this 6.5 billion solar mass black hole was released. That now-iconic image was the result of one week of observations from April 2017 and used telescopes at seven different sites. That one observing run built on the successes of four prior observing sessions that were at a lower resolution but that were, nonetheless, good enough to capture some highlights of what was happening. 

And by highlights, I literally mean that these earlier images were able to capture the changing position of the hot spot in the ring. According to Thomas Krichbaum, a researcher on this project: The data analysis suggests that the orientation and fine structure of the ring vary with time. This gives a first impression on the dynamical structure of the accretion flow, which surrounds the event horizon. Studying this region will be crucial for a better understanding of how black holes accrete matter and launch relativistic jets. 

These results are published in a new paper in The Astrophysical Journal with first author Maciek Wielgus. The press release related to this story explains: The gas falling onto a black hole heats up to billions of degrees, ionizes, and becomes turbulent in the presence of magnetic fields. Since the flow of matter is turbulent, the ring brightness appears to glitter with time, which challenges some theoretical models of accretion. 

As always, the universe is weirder than we expected.

More Information

Max Planck Institute press release 

“Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope,” M. Wielgus et al., 2020 Sep. 23, Astrophysical Journal