3C 66A

3C 66A
Hubble Legacy Archive WFPC2 image of 3C 66A
(brightest object on the far right)
Observation data (Epoch J2000)
ConstellationAndromeda
Right ascension02h 22m 39.612s[1]
Declination+43° 02′ 07.80″[1]
Redshift0.444[1][2]
Distance4.5 billion light-years
(Light travel time)[2]
5.4 billion light-years
(present)[2]
TypeBLLAC[2]
Apparent magnitude (V)15.5[1][2]
Other designations
2E 558, 2EG J0220+4228, B3 0219+428A, QSO B0219+4248[1]
See also: Quasar, List of quasars

3C 66A is a blazar[1][2] located in the constellation Andromeda.

The "distance" of a far away galaxy depends on the distance measurement used. With a redshift of 0.444,[1][2] light from this active galaxy is estimated to have taken around 4.5 billion years to reach Earth.[2] But as a result of the expansion of the Universe, the present (co-moving) distance to this galaxy is about 5.4 billion light-years (1647 Mpc).[2] Even at this great distance this blazar has an apparent magnitude of about 15.5.[1] Although 0.444 is used as the common redshift value, 0.3347 is a new strict lower limit "inferred through observing the far-UV absorption by the low-z IGM."[3]

3C 66A underwent an optical outburst in 2007 August, as monitored by the Tuorla blazar monitoring program.[4] The event was monitored by the Whole Earth Blazar Telescope project.

  1. ^ a b c d e f g h "3C 66A". SIMBAD Astronomical Database. Retrieved 2010-04-01.
  2. ^ a b c d e f g h i "NASA/IPAC Extragalactic Database". Results for 3C 066A. Retrieved 2010-04-01.
  3. ^ Furniss, Amy (May 10, 2013). "THE FIRM REDSHIFT LOWER LIMIT OF THE MOST DISTANT TeV-DETECTED BLAZAR PKS 1424+240". Astrophysical Journal Letters. 768 (2): L31. arXiv:1304.4859. Bibcode:2013ApJ...768L..31F. doi:10.1088/2041-8205/768/2/L31. S2CID 21291053.
  4. ^ Errando, Manel; Lindfors, Elina; Mazin, Daniel; Prandini, Elisa; Tavecchio, Fabrizio (2009). "A TeV source in the 3C 66A/B region". arXiv:0907.0994 [astro-ph.HE].