Hoag's Object

Hoag's Object
Hoag's Object, taken by the Hubble Space Telescope in July 2001
Observation data (J2000 epoch)
ConstellationSerpens Caput
Right ascension15h 17m 14.4s[1]
Declination+21° 35′ 08″[1]
Redshift12740±50 km/s[1][2]
Distance612.8±9.4 Mly (187.9±2.9 Mpc)[2][a]
Apparent magnitude (B)16.2[1]
Characteristics
Type(RP)E0 or (RP)SA0/a[3]
Size45.41 kiloparsecs (148,000 light-years)[1][4]
(diameter; D25 isophote)
Apparent size (V)0.28′ × 0.28′[1]
Notable featuresRing galaxy
Other designations
PGC 54559,[1] PRC D-51[1]

Hoag's Object is an unusual ring galaxy in the constellation of Serpens Caput.[5] It is named after Arthur Hoag, who discovered it in 1950 and identified it as either a planetary nebula or a peculiar galaxy.[6] The galaxy has a D25 isophotal diameter of 45.41 kiloparsecs (148,000 light-years).[1]

  1. ^ a b c d e f g h i "NED results for Hoag's Object". NASA/IPAC Extragalactic Database. Retrieved 2016-06-28.
  2. ^ a b Cite error: The named reference OConnelletal1974 was invoked but never defined (see the help page).
  3. ^ Buta, Ronald J. (2017). "Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database". Monthly Notices of the Royal Astronomical Society. 471 (4): 4027–4046. arXiv:1707.06589. Bibcode:2017MNRAS.471.4027B. doi:10.1093/mnras/stx1829.
  4. ^ Adelman-Mccarthy, Jennifer K.; et al. (2008). "The Sixth Data Release of the Sloan Digital Sky Survey". The Astrophysical Journal Supplement Series. 175 (2): 297–313. arXiv:0707.3413. Bibcode:2008ApJS..175..297A. doi:10.1086/524984.
  5. ^ Specktor, Brandon (3 December 2019). "Hoag's Object Is a Galaxy Within a Galaxy Within a Galaxy (and Nobody Knows Why)". Live Science. Retrieved 3 December 2019.
  6. ^ A.A. Hoag (1950). "A peculiar object in Serpens". Astronomical Journal. 55: 170. Bibcode:1950AJ.....55Q.170H. doi:10.1086/106427.