The name signifies that it was the 273rd object (ordered by right ascension) of the Third Cambridge Catalog of Radio Sources (3C), published in 1959. After accurate positions were obtained using lunar occultation by Cyril Hazard at the Parkes Radio Telescope, the radio source was quickly associated with an optical counterpart, an unresolved "stellar object". In 1963, Maarten Schmidt and Bev Oke published a pair of papers in "Nature" reporting that 3C 273 has a substantial redshift of 0.158, placing it several billion light-years away.