The Hubble Space Telescope has also imaged the fainter host galaxies of quasars, so astronomers know for sure that quasars are the active cores of some galaxies. Quasars are so bright that they can be seen at vast distances across the universe the most distant known quasar is seen as it appeared 13.13 billion years ago. Yes! The closest, brightest quasar - called 3C 273 - is even visible to amateur astronomers with at least an 8-inch telescope, or astro-imagers, as it shines at magnitude 12.9 in the constellation of Virgo. Early in the history of the universe, this may have been streams of material flowing onto the galaxy via filaments in the cosmic web later on, the gravitational tidal forces resulting from galaxy collisions and close encounters may have also caused some quasars to light up. Quasars are formed when an event causes a huge amount of gas to pile onto the central supermassive black hole in a galaxy. The disk, along with the spin of the black hole and the magnetic fields entwined between the two, is the source of the jet that also gives quasars much of their brightness. It is this gas, in the form of a spiraling 'accretion disk' around the black hole, that becomes very hot and emits all the light. Yes, a quasar is just a black hole, but not any black hole - it is a supermassive black hole that is growing rapidly by gorging on huge amounts of gas. Quasar FAQs Is a quasar just a black hole?
