The most gigantic ones, known as “supermassive” black holes, can weigh millions to billions times the mass of the Sun. These giants usually live in the centers of galaxies. Our own galaxy, the Milky ...
A quasar is a rare and extremely luminous type of supermassive black hole that is located at the center of a galaxy. NASA's Hubble Space Telescope unexpectedly finds double Quasar in distant universe.