NGC 681


NGC 681
legacy surveys image of NGC 681
Observation data (J2000 epoch)
ConstellationCetus
Right ascension01h 49m 10.829s[1]
Declination−10° 25′ 35.13″[1]
Redshift0.00587 ± 0.00002[1]
Heliocentric radial velocity1760.4 ± 6.6 km/s[1]
Distance~66.5 million ly (20.39 ± 1.45 Mpc)[1]
Apparent magnitude (V)12[2]
Characteristics
TypeSAB(s)ab
Mass1.9×1010[3] M
Mass/Light ratio3.6[3] M/L
Size~29.07 kpc (diameter)[1]
Apparent size (V)2.70 × 1.8 arcmin[2][4]
Other designations
MCG -02-05-052, PGC 6671[5]

NGC 681 is an intermediate spiral galaxy in the constellation of Cetus, located approximately 66.5 million light-years from Earth.[1][2][4]

SDSS image of NGC 681

Observation history

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NGC 681 was discovered by the German-born British astronomer William Herschel on 28 November 1785 and was later also observed by William's son, John Herschel.[2] John Louis Emil Dreyer, compiler of the first New General Catalogue of Nebulae and Clusters of Stars, described NGC 681 as being a "pretty faint, considerably large, round, small (faint) star 90 arcsec to [the] west" that becomes "gradually a little brighter [in the] middle".[2]

Physical characteristics

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NGC 681 shares many structural similarities with the Sombrero Galaxy, M104, although it is smaller, less luminous, and less massive. Its thin, dusty disc is seen almost perfectly edge-on and features a small, very bright nucleus in the center of a very pronounced bulge.[6] Distinctly unlike M104, NGC 681's disc contains many H II regions, where star formation is likely to be occurring.[3][6] The galaxy has a mass of 1.9×1010 M, a mass-to-light ratio of 3.6 , and a spiral pattern which is asymmetrical.[3]

See also

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References

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  1. ^ a b c d e f g "NGC 681 NASA/IPAC Extragalactic Database Results". ned.ipac.caltech.edu. Retrieved November 2, 2018.
  2. ^ a b c d e "New General Catalog Objects: NGC 650 - 699". cseligman.com. Retrieved November 2, 2018.
  3. ^ a b c d Burbridge, E. M.; G.R., Burbridge; Prendergast, K.H. (1965). "Rotation and Mass of the SA Galaxy, NGC 681". Astrophysical Journal. 142: 154–159. Bibcode:1965ApJ...142..154B. doi:10.1086/148270. hdl:2060/19650010085.
  4. ^ a b "Revised NGC Data for NGC 681". spider.seds.org. Retrieved November 2, 2018.
  5. ^ "NGC 681". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-19.
  6. ^ a b Faber, S. M.; Balick, B.; Gallagher, J. S.; Knapp, G. R. (1977). "The neutral hydrogen content, stellar rotation curve, and mass-to-light ratio of NGC 4594, the "Sombrero" galaxy". The Astrophysical Journal. 214: 383–389. Bibcode:1977ApJ...214..383F. doi:10.1086/155260. ISSN 0004-637X.
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  • Media related to NGC 681 at Wikimedia Commons