3C 147 (B0538+498) is a compact steep-spectrum (CSS) quasar[3] that was discovered in 1964. It is located in the constellation Auriga not far in the sky from the 5th magnitude star Omicron Aurigae.

3C 147
Hubble Legacy Archive WFPC2 image of 3C 147
Observation data (Epoch J2000)
Right ascension05h 42m 36.138s[1]
Declination+49° 51′ 07.23″[1]
Distance5.1 billion light-years
(Light travel time)[2]
6.4 billion light-years
Seyfert 1[1][2]
Apparent magnitude (V)17.8[1][2]
Other designations
PGC 2355407, 2E 1506, 2MASS J05423614+4951071, QSO B0538+498[1]
See also: Quasar, List of quasars

The "distance" of a far away galaxy depends on what distance measurement you use. With a redshift of 0.545,[1][2] light from this active galaxy is estimated to have taken around 5.1 billion years to reach us.[2] But as a result of the expansion of the Universe, the present (co-moving) distance to this galaxy is about 6.4 billion light-years (1974 Mpc).[2]

Very Long Baseline Array (VLBA) observations have identified a complex central region that is dominated by two bright components, A and B.[3] The separation between the two central components of the source seems to be increasing with an apparent velocity (superluminal motion) of 1.2 ± 0.4 c.[3]

3C 147 is one of four primary calibrators used by the Very Large Array (along with 3C 48, 3C 138, and 3C 286). Visibilities of all other sources are calibrated using observed visibilities of one of these four calibrators.[4]

See alsoEdit


  1. ^ a b c d e f g "3C 147". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-04-21.
  2. ^ a b c d e f g h i "NASA/IPAC Extragalactic Database". Results for 3C 147. Retrieved 2010-04-21.
  3. ^ a b c d Rossetti, A.; Mantovani; Dallacasa; Junor; Salter; Saikia (2009). "VLBA polarimetric observations of the CSS quasar 3C 147". Astronomy & Astrophysics. 504 (3): 741–749. arXiv:0910.2146. Bibcode:2009A&A...504..741R. doi:10.1051/0004-6361/200811190.
  4. ^ Witz, Stephan W. (4 December 2015). "Calibration and Flux Density Scale". National Radio Astronomy Observatory. Retrieved 15 May 2016.

External linksEdit

  • Wikisky image of 3C 147 (PGC 2355407)