Astronomers using NASA’s Chandra X-ray Observatory have discovered what they believe are 12 stellar-mass black holes gathered around Sagittarius A*, the supermassive black hole in the Milky Way’s center, leading them to conclude there are probably 10,000 such objects spread throughout the central region of our Galaxy. Their work appears in the April 5, 2018 issue of the journal Nature. The region around the center of our Milky Way Galaxy glows...