X-ray astronomers find evidence of a black hole at the center of a dwarf galaxy gobbling up a star; this is the first such event ever filmed.
The European Southern Observatory announces the discovery of Earth's closest-known black hole (HR 6819). The invisible object in the QV Telescopii system has a mass at least four times that of our Sun, and is roughly 1,000 light years (10 quadrillion km) from Earth in the constellation Telescopium.
Katie Bouman and scientists at the Event Horizon Telescope project release the first ever photograph of the event horizon of a black hole, that of the supermassive black hole at the center of Messier 87 galaxy, taken using a network of eight radio telescopes around the world.
A study published to the journal "Nature" finds dozens of potential stellar mass black holes in the Galactic Center, suggesting there may be as many as 20,000 orbiting the supermassive black hole Sagittarius A*.
Researchers at the Breakthrough Listen initiative announce they have detected 15 new powerful fast radio bursts (FRB) from FRB 121102, located in a dwarf galaxy about three billion light-years from Earth. FRB 121102 was first detected in 2012, and gained further attention after FRBs were detected from there again in 2015.
Space telescope observations indicate that the supernova RCW 86, first seen by Chinese astronomers in 185 AD, expanded at an unprecedented rate due to the formation of a vacuum-like "cavity" around it in the early stages of the death of its star. The supernova's rapid expansion had previously been one of astronomy's most enduring mysteries.