In very general terms, black holes come in two sizes, and are found in two different circumstances. • Stellar Black holes are the remnants of massive stars after their type II supernova detonations. The most famous example is Cygnus X-1. Although there are several other possible candidates for stellar black holes in our home galaxy. • Supermassive black holes exist in the very center of many, if not most, galaxies, including our own Milky Way. Sagittarius A* is our nearest example of a supermassive black hole and is calculated to have millions of times the Sun’s mass. The big news in early 2019 is the first image of the event horizon around the supermassive black hole in the galaxy M87.