(nem volt segitség)
[[Image:Quasar 3C 273.jpg|thumb|left|200px| A 3C 273 a Hubble Űrtávcső felvételén. [[NASA]]/[[ESA]].]]
3C 273 is a radio-loud quasar, and was also one of the first extragalactic [[X-ray]] sources discovered in [].
<ref name="Uchiyamaetal2006" />
The [[luminosity]] is variable at nearly every [[wavelength]] from [[radio waves]] to [[Gamma rays]] on timescales of a few days to decades.
[[Polarization (waves)|Polarization]] with coincident orientation has been observed in radio, infrared, and optical light being emitted from the large-scale jet; these emissions are therefore almost certainly [[synchrotron radiation|synchrotron]] in nature,<ref name="Uchiyamaetal2006" />
[[VLBI]] radio observations of 3C 273