The Event Horizon Telescope (EHT) is able to resolve images down to 15 micro-arcseconds which allows the telescope to be able to achieve a resolution that is able to view a black hole. The Milky Way's Central Black hole, the Sagittarius A-Star, a black hole that has the mass of 4 million M_sun, radius of 13 million kilometers, and located 25,000 light years away. And when everything is calculated, the size of resolution comes out to roughly 8 micro-arcseconds, but due to the way gravitational lensing affects it, it boosts the size to roughly 50 micro-arcseconds which allows the EHT to be able to detect it.
The EHT was able to detect the magnetic fields of Sagittarius A-Star at roughly 1.3mm, and compared to how the light was measured polarized. And on the Sagittarius A-Star, the polarized light was being emitted by electrons traveling on the magnetic fields, but the data reveals that the magnetic fields were disorderly with some parts chaotic in pattern, and others in a more organized formation. Researchers are hoping that in the future, more upgrades will be added to gather more data and hopefully be able to image an event horizon for the first time.
Sources : https://www.cfa.harvard.edu/news/2015-28
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