Quasar 3C 273. Coloured Chandra X-ray telescope image of quasar 3C 273. A quasar results from the activity of a supermassive black hole at the core of a galaxy. This view shows the area between the core (top left) and the start of the powerful jet (lower centre). The jet is thought to be a stream of material accelerated and directed by the strong gravitational and electromagnetic fields of the black hole. Quasars are among the most powerful sources of radiation in the sky and among the most distant objects in the universe. 3C 273 is the nearest quasar known, at a distance of about 2000 million light years. The brightest quasar, it was the first to be discovered, in the early 1960s.