Quasar 3C 273,optical image. The quasar (centre) is seen with a jet pointing towards lower right. A quasar results from the activity of a supermassive black hole at the core of a galaxy. The jet,some 150,000 light years long,is thought to be ejected material accelerated by the black hole. Quasars are among the most powerful and distant sources of radiation in the universe. 3C 273,2000 million light years away,is the nearest and brightest of the quasars. In 1962,it was the first quasar to be recognised as a quasar. Photographed by the KPNO 4-metre telescope,Kitt Peak,Arizona,USA |