Astronomers discovered that the shadow of the m87 black hole wobbles

The Event Horizon Telescope is an array of telescopes that uses a method called Very Long Baseline Interferometry (VLBI) to make a virtual radio reflector with a dish diameter just like the scale of Earth. 

In the period between 2009-2013, M87* (the supermassive region within the galaxy M87) was observed with prototype EHT telescopes, at four different sites. Eventually, the whole EHT array came into operation in 2017, with seven telescopes located in five locations around the Earth.

Although the observations from 2009-2013 contained much less data than those from 2017 (lacking the capacity to supply an image of the part at that time in time), the EHT team was able to identify changes within the appearance of M87* between 2009 and 2017 using statistical models.

The researchers concluded that the diameter of the black hole's shadow remains in step with the predictions of Einstein's general theory of relativity for black holes of 6.5 billion solar masses. But they also found something unexpected: the crescent-shaped ring of hot plasma around M87* wobbles! it's the primary time astronomers have glimpsed the dynamic accretion structure so near the event horizon of a region, where gravity is extreme.

Snapshots of the looks of M87 *, obtained with images and geometrical models and also the EHT array between 2009 and 2017. The diameter of the rings is that the same, but the situation of the brilliant side varies. - (Image Credit: M. Wielgus, D. Pesce & the EHT Collaboration)

One of the researchers, Sara Issaoun, stated in a very NOVA handout that in applying the knowledge gained from the 2017 observations to older data, they found that the ring's size remained identical while the radiation from the gas around it changed over the years.

Professor of Theoretical High Energy Astrophysics at the University of Amsterdam, Sera Markoff, supplemented this statement by explaining that the brightness of the spot within the ring is depending on the properties of gas surrounding the part, but also on its 'spin' and their relative orientations. The research team has already been able to discard several theoretical models for accretion, allowing scientists to check the laws of gravity around black holes more adequately.

If you're curious about a more detailed outlay of the study on M87*, make sure to test out the paper listed below this text. The EHT astronomers now possess a wealth of information on the dynamics of black holes. The team is currently analyzing 2018 data, which involved an extra telescope (in Greenland). In 2021, the array are going to be expanded even further with two additional telescopes!