M87* One Year Later: Proof of a persistent black hole shadow

The Event Horizon Telescope (EHT) Collaboration, with contribution by Dutch  astronomers, has released new images of M87*, the supermassive black hole at the center of the galaxy Messier 87, using data from observations taken in April 2018.  With the participation of the newly commissioned Greenland Telescope and a dramatically improved recording rate across the array, the 2018 observations give us a view of the source independent from the first observations in 2017.  A recent paper titeled “The persistent shadow of the supermassive black hole of M87” published in the journal Astronomy & Astrophysics presents new images from the 2018 data that reveal a familiar ring the same size as the one observed in 2017.  This bright ring surrounds a deep central depression, “the shadow of the black hole,” as predicted by general relativity.  Excitingly, the brightness peak of the ring has shifted by about 30º compared to the images from 2017, which is consistent with our theoretical understanding of variability from turbulent material around black holes.