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NGC 818

NGC 818
NGC 818 imaged by Pan-STARRS
Observation data (J2000 epoch)
ConstellationAndromeda
Right ascension02h 08m 44.5464s[1]
Declination+38° 46′ 37.596″[1]
Redshift0.014156±0.0000130[1]
Heliocentric radial velocity4,244±4 km/s[1]
Distance168.62 ± 8.37 Mly (51.700 ± 2.565 Mpc)[1]
Group or cluster[CHM2007] LDC 148
Apparent magnitude (V)13.20[1]
Characteristics
TypeSABc[1]
Size~171,700 ly (52.64 kpc) (estimated)[1]
Apparent size (V)3.0′ × 1.3′[1]
Other designations
IRAS 02057+3832, 2MASX J02084451+3846381, UGC 1633, MCG +06-05-086, PGC 8185, CGCG 522-116[1]

NGC 818 is an intermediate spiral galaxy in the constellation of Andromeda. Its velocity with respect to the cosmic microwave background is 4,010±17 km/s, which corresponds to a Hubble distance of 192.9 ± 13.5 Mly (59.14 ± 4.15 Mpc).[1] Additionally, 14 non-redshift measurements give a closer mean distance of 168.62 ± 8.37 Mly (51.700 ± 2.565 Mpc).[2] It was discovered by German-British astronomer William Herschel on 18 October 1786.[3][4]

NGC 818 has a possible active galactic nucleus, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars.[5][6]

Galaxy group

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NGC 818 is a member of a galaxy group known as [CHM2007] LDC 148. The other galaxies in the group are NGC 834, NGC 841, NGC 845, UGC 1673, and UGC 1721.[7][8]

Supermassive black hole

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According to a paper based on measurements of the near-infrared K-band luminosity of the galaxy's bulge, NGC 818 has a supermassive black hole with a mass of 1×107.1M☉ (13 million solar masses).[9]

Supernova

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One supernova has been observed in NGC 818:

See also

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References

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  1. ^ a b c d e f g h i j k "Results for object NGC 818". NASA/IPAC Extragalactic Database. NASA and Caltech. Retrieved 19 December 2025.
  2. ^ "Distance Results for NGC 818". NASA/IPAC Extragalactic Database. NASA. Retrieved 19 December 2025.
  3. ^ Herschel, William (1789). "Catalogue of a Second Thousand of New Nebulae and Clusters of Stars; with a Few Introductory Remarks on the Construction of the Heavens". Philosophical Transactions of the Royal Society of London. 79: 212–255. Bibcode:1789RSPT...79..212H. doi:10.1098/rstl.1789.0021.
  4. ^ Seligman, Courtney. "New General Catalogue Objects: NGC 818". Celestial Atlas. Retrieved 19 December 2025.
  5. ^ Asmus, D.; Greenwell, C. L.; Gandhi, P.; Boorman, P. G.; Aird, J.; Alexander, D. M.; Assef, R. J.; Baldi, R. D.; Davies, R. I.; Hönig, S. F.; Ricci, C.; Rosario, D. J.; Salvato, M.; Shankar, F.; Stern, D. (2020). "Local AGN survey (LASr): I. Galaxy sample, infrared colour selection, and predictions for AGN within 100 MPC". Monthly Notices of the Royal Astronomical Society. 494 (2): 1784. arXiv:2003.05959. Bibcode:2020MNRAS.494.1784A. doi:10.1093/mnras/staa766.
  6. ^ "NGC 818". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 19 December 2025.
  7. ^ Crook, Aidan C.; Huchra, John P.; Martimbeau, Nathalie; Masters, Karen L.; Jarrett, Tom; Macri, Lucas M. (2007). "Groups of Galaxies in the Two Micron All Sky Redshift Survey". The Astrophysical Journal. 655 (2): 790. arXiv:astro-ph/0610732. Bibcode:2007ApJ...655..790C. doi:10.1086/510201.
  8. ^ "[CHM2007] LDC 148". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 19 December 2025.
  9. ^ Dong, X. Y.; De Robertis, M. M. (2006). "Low-Luminosity Active Galaxies and Their Central Black Holes". The Astronomical Journal. 131 (3): 1236. arXiv:astro-ph/0510694. Bibcode:2006AJ....131.1236D. doi:10.1086/499334.
  10. ^ Pollas, C.; Emond, J.-B.; Michel, F.; Prugniel, P.; Kirshner, R.; Gordon, S. (1992). "Supernova 1992az in NGC 818". International Astronomical Union Circular (5625): 1. Bibcode:1992IAUC.5625....1P.
  11. ^ "SN 1992az". Transient Name Server. IAU. Retrieved 19 December 2025.
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  • Media related to NGC 818 at Wikimedia Commons
  • NGC 818 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images