View source for 3C 273

{{Quasar
  | name = [[Third Cambridge Catalogue of Radio Sources|3C]] 273
  | image = Best image of bright quasar 3C 273.jpg
  | caption= Quasar 3C 273 taken by [[Hubble Space Telescope]].<ref>{{cite news|title=Best image of bright quasar 3C 273|url=http://www.spacetelescope.org/images/potw1346a/|accessdate=20 November 2013|newspaper=ESA/Hubble Picture of the Week}}</ref>
  | epoch = [[J2000]]
  | ra = {{RA|12|29|06.7}}<ref name="ned">{{cite web
  | title=NASA/IPAC Extragalactic Database
  | work=Results for 3C 273
  | url=http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=3C+273&extend=no
  | accessdate=2006-10-26 }}</ref>
  | dec = {{DEC|+02|03|09}}<ref name="ned" />
  | constellation name = [[Virgo (constellation)|Virgo]]
  | z = 0.158339 ± 0.000067<ref name="ned" />
  | type = [[Blazar]]; Sy1<ref name="ned" />
  | dist_ly = {{convert|2.443|Gly|Mpc|0|abbr=on|lk=on}}<ref name=XJET>{{cite web
 |date=2008-01-11
 |title=3C 273
 |publisher=XJET: X-Ray Emission from Extragalactic Radio Jets
 |url=http://hea-www.harvard.edu/XJET/source-d.cgi?3C_273
 |accessdate=2010-04-05}}</ref><ref name="Uchiyamaetal2006"/> (luminosity distance)
  | appmag_v = 12.9<ref name="ned" />
  | size_v =
  | notes = optically-brightest quasar, first spectrum of a quasar
  | names = [[Principal Galaxies Catalogue|PGC]] 41121<ref name="ned" /> and [[Hipparcos Catalogue|HIP]] 60936
| mass=886 ± 187 × 10<sup>6</sup>
| luminosity=10<sup>12</sup>
}}

'''3C 273''' is a [[quasar]] located in the [[constellation]] [[Virgo (constellation)|Virgo]]. It was the first quasar ever to be identified.

It is the [[optic]]ally brightest quasar in the sky ([[apparent magnitude|m]] ~12.9), and one of the closest with a [[redshift]], ''z'', of 0.158.<ref name="Schmidt1963" />  A [[luminosity distance]] of D<sub>L</sub> = {{convert|749|Mpc|Gly|1|lk=on}} may be calculated from ''z''.<ref name="Uchiyamaetal2006">{{cite journal
  | display-authors=6
  | author=Uchiyama, Yasunobu
  | author2=Urry, C. Megan
  | author3=Cheung, C. C.
  | author4=Jester, Sebastian
  | author5=Van Duyne, Jeffrey
  | author6=Coppi, Paolo
  | author7=Sambruna, Rita M.
  | author8=Takahashi, Tadayuki
  | author9=Tavecchio, Fabrizio
  | author10=Maraschi, Laura
  | title=Shedding New Light on the 3C 273 Jet with the Spitzer Space Telescope
  | journal=The Astrophysical Journal
  | date=2006
  | volume=648
  | issue=2
  | pages=910–921
  | bibcode=2006ApJ...648..910U 
  | doi=10.1086/505964
|arxiv = astro-ph/0605530 }}</ref>  It is also one of the most luminous quasars known, with an [[absolute magnitude]] of −26.7,<ref name="3C 273 article">{{Cite journal|title=The Quasi-Stellar Radio Sources 3C 48 and 3C 273|url=http://adsabs.harvard.edu/full/1964ApJ...140....1G|bibcode=1964ApJ...140....1G|journal=The Astrophysical Journal|accessdate=25 April 2014|doi = 10.1086/147889 }}</ref> meaning that if it were only as distant as [[Pollux (star)|Pollux]] (~10 [[parsec]]s) it would [[Apparent magnitude|appear nearly as bright]] in the sky as the [[Sun]]. Since the sun's [[absolute magnitude]] is 4.83, it means that the quasar is over 4 trillion times more [[Luminosity|luminous]] than the Sun at visible wavelengths.  The mass of its central black hole has been measured to be 886 ± 187 million [[solar mass]]es through broad emission-line [[reverberation mapping]].<ref name="Petersonetal2004">{{cite journal
  | display-authors=6
  | author=Peterson, B. M.
  | author2=Ferrarese, L.
  | author3=Gilbert, K. M.
  | author4=Kaspi, S.
  | author5=Malkan, M. A.
  | author6=Maoz,D. 
  | author7=Merritt, D. 
  | author7-link=David Merritt
  | author8=Netzer, H.
  | author9=Onken, C. A.
  | author10=Pogge, R. W.
  | author11=Vestergaard, M.
  | author12=Wandel, A.
  | title=Central Masses of AGNs. II.
  | journal=The Astrophysical Journal
  | date=2004
  | volume=613
  | issue=2
  | pages=682–699
  | doi=10.1086/423269
| bibcode=2004ApJ...613..682P|arxiv = astro-ph/0407299 }}</ref>

==Large-scale jet==
The quasar has a large-scale visible [[astrophysical jet|jet]], which measures ~{{convert|200|kly|kpc|-1|abbr=on}} long, having an apparent size of 23&Prime;.<ref name="Uchiyamaetal2006" /> In 1995 optical imaging of the jet using the [[Hubble Space Telescope]] revealed a structured [[morphology (astronomy)|morphology]] evidenced by repeated bright knots interlaced by areas of weak emission.<ref name="Uchiyamaetal2006" />

==History==
The name signifies that it was the 273rd object (ordered by [[right ascension]]) of the Third [[University of Cambridge|Cambridge]] Catalog of Radio Sources ([[Third Cambridge Catalogue of Radio Sources|3C]]), published in 1959.  After accurate positions were obtained using [[lunar occultation]] by [[Cyril Hazard]] at the [[Parkes Radio Telescope]],<ref name="HazardMackeyShimmins63">{{cite journal
 | author=Hazard, C.
 | author2=Mackey, M. B.
 | author3=Shimmins, A. J.
 | title=Investigation of the Radio Source 3C273 by the method of Lunar Occultations
 | journal=Nature
 | date=1963
 | volume=197
 | issue=4872
 | pages=1037
 | bibcode=1963Natur.197.1037H
 | doi=10.1038/1971037a0}}</ref>
the radio source was quickly associated with an [[optical]] counterpart, an unresolved ''stellar object''.  In 1963, [[Maarten Schmidt]]<ref name="Schmidt1963">{{cite journal
| author=Schmidt, M.
| title=3C 273 : A Star-Like Object with Large Red-Shift
| journal=Nature
| date=1963
| volume=197
| issue=4872
| pages=1040
| bibcode=1963Natur.197.1040S
| doi=10.1038/1971040a0}}</ref> and [[Bev Oke]]<ref name="Oke1963">{{cite journal
| author=Oke, J. B.
| title=Absolute Energy Distribution in the Optical Spectrum of 3C 273
| journal=Nature
| date=1963
| volume=197
| issue=4872
| pages=1040
| bibcode=1963Natur.197.1040O
| doi=10.1038/1971040b0}}</ref> published a pair of papers in ''[[Nature (journal)|Nature]]'' reporting that 3C 273 has a substantial [[redshift]] of 0.158, placing it several billion [[light-year]]s away.

Prior to the discovery of 3C 273, several other radio sources had been associated with optical counterparts, the first being [[3C 48]].  Also, many [[Active Galactic Nucleus|active galaxies]] had been misidentified as [[variable star]]s, including the famous [[BL Lacertae|BL Lac]], [[W Comae Berenices|W Com]], and [[AU Canum Venaticorum|AU CVn]].  However, it wasn't understood what these objects were, since their spectra were unlike those of any known stars.  Its spectrum did not resemble that of any normal stars with typical stellar elements. 3C 273 was the first object to be identified as what we now know [[quasar]]s to be—extremely luminous objects at cosmological distances.

[[Image:Quasar 3C 273.jpg|thumb|left|200px|3C 273 as imaged by the Hubble Space Telescope's Advanced Camera for Surveys. Credit: [[NASA]]/[[ESA]].]]

3C 273 is a radio-loud quasar, and was also one of the first extragalactic [[X-ray]] sources discovered in 1970.
However, even to this day, the process which gives rise to the X-ray emissions is controversial.<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" /> radiation that is created by a jet of charged particles moving at [[relativistic speed]]s.
Such jets are believed to be created by the interaction of the central [[black hole]] and the [[accretion disk]].  [[VLBI]] radio observations of 3C 273 have revealed [[proper motion]] of some of the radio emitting regions, further suggesting the presence of relativistic jets of material. <ref>{{Cite journal|doi=10.1038/290365a0|title=Superluminal expansion of quasar 3C273|date=1981|last1=Pearson|first1=T. J.|last2=Unwin|first2=S. C.|last3=Cohen|first3=M. H.|last4=Linfield|first4=R. P.|last5=Readhead|first5=A. C. S.|last6=Seielstad|first6=G. A.|last7=Simon|first7=R. S.|last8=Walker|first8=R. C.|journal=Nature|volume=290|issue=5805|pages=365|bibcode = 1981Natur.290..365P }};</ref> <ref>{{Cite journal|doi=10.1038/354374a0|title=Large-scale superluminal motion in the quasar 3C273|date=1991|last1=Davis|first1=R. J.|last2=Unwin|first2=S. C.|last3=Muxlow|first3=T. W. B.|journal=Nature|volume=354|issue=6352|pages=374|bibcode = 1991Natur.354..374D }}</ref>

== Host galaxy ==
3C 273 lies at the center of a giant [[elliptical galaxy]] with an [[apparent magnitude]] of 16 and an apparent size of 30 [[arc second]]s.<ref name="Bahcall97">{{cite journal
 | author=Bahcall, John N.
 | author2=Kirhakos, Sofia
 | author3=Saxe, David H.
 | author4=Schneider, Donald P.
 | title=Hubble Space Telescope Images of a Sample of 20 Nearby Luminous Quasars
 | journal=The Astrophysical Journal
 | date=1997
 | volume=479
 | pages=642
 |arxiv=astro-ph/9611163
 | bibcode=1997ApJ...479..642B
 | doi=10.1086/303926}}</ref>

== Observation ==
[[File:3C273 Chandra.jpg|thumb|Quasar 3C 273, with its jet. Image by [[Chandra X-ray Observatory]]]]

3C 273 is visible in May in both the [[northern hemisphere|northern]] and [[southern hemisphere]]s. Situated in the Virgo constellation, It is bright enough to be observed with larger [[amateur astronomy|amateur telescopes]]. Due in part to its radio luminosity and its discovery as the first identified quasar, 3C 273's [[right ascension]] in the [[Fifth Fundamental Catalog]] (FK5) is used to standardize the positions of 23 extragalactic radio sources used to define the [[International Celestial Reference System]] (ICRS).<ref name="def_syst">{{cite web    
 | url=http://hpiers.obspm.fr/icrs-pc/icrs/def_syst.html
 | title=Definition of ICRS Axes
 | author=International Earth Rotation & Reference Systems Service
 | accessdate=11 January 2012}}</ref>

Given its distance from [[Earth]] and visual magnitude, 3C 273 is the most distant celestial object average amateur astronomers are likely to see through their telescopes.

==References==
{{reflist}}

== External links ==
* [http://isdc.unige.ch/3c273/ 3C 273's Database at the INTEGRAL Science Data Centre (ESA)]
* [http://www.perseus.gr/Astro-DSO-QSO-3C273.htm Detailed CCD image of 3C 273 based on 30 min total exposure]
* [http://astro.neutral.org/imagehtml/20050408_3c273.html Amateur 3C 273 Redshift Measurement]
* [http://www.nightskyinfo.com/archive/3c273_quasar NightSkyInfo.com – 3C 273]
* [http://www.sky-map.org/?object=3C%20273&zoom=12&img_source=SDSS  SKY-MAP.ORG SDSS image of 3C 273]
* [https://web.archive.org/web/20090123191313/http://www.aavso.org/vstar/vsots/spring05.shtml The Quasar 3C 273: Spring 2005 – Variable Star Of The Season AAVSO]
* {{WikiSky|z=12}}

{{Sky|12|29|06.7|+|02|03|09|2440000000}}

[[Category:Virgo (constellation)]]
[[Category:OVV quasars]]
[[Category:3C objects|273]]