Astronomy:NGC 251
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| NGC 251 | |
|---|---|
 SDSS image of NGC 251 | |
| Observation data (J2000 epoch) | |
| Constellation | Pisces |
| Right ascension | 00h 47m 54.0517s[1] |
| Declination | +19° 35′ 48.788″[1] |
| Redshift | 0.015184[2] |
| Helio radial velocity | 4556 km/s[2] |
| Distance | 204.36 ± 12.64 Mly (62.657 ± 3.876 Mpc)[2] |
| Apparent magnitude (B) | 14.6[3] |
| Characteristics | |
| Type | Sc[2] |
| Size | 149,300 ly (45,780 pc)[2][note 1] |
| Apparent size (V) | 2.4′ × 1.9′[2] |
| Other designations | |
| KPG 015B, UGC 490, PGC 2806[3] | |
NGC 251 is a spiral galaxy in the constellation of Pisces. Its velocity with respect to the cosmic microwave background for is 4,224±23 km/s, which corresponds to a Hubble distance of 203.2 ± 14.3 Mly (62.30 ± 4.37 Mpc).[2] Additionally, six non redshift measurements give a distance of 205.32 ± 5.54 Mly (62.950 ± 1.699 Mpc).[4] It was discovered on October 15, 1784, by German-British astronomer William Herschel.[5]
According to I.D. Karachentsev, NGC 251 forms an isolated galaxy pair with UGC 477.[6]
One supernova has been observed in NGC 251: SN 2023rky (type II, mag. 18.6) was discovered by the Zwicky Transient Facility on 6 September 2023.[7]
Notes
- ↑ POSS1 103a-O values used.
See also
References
- ↑ 1.0 1.1 Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W. et al. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal 131 (2): 1163–1183. doi:10.1086/498708. ISSN 0004-6256. Bibcode: 2006AJ....131.1163S.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "NED results for object NGC 0251". National Aeronautics and Space Administration / Infrared Processing and Analysis Center. http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC+251&extend=no&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES.
- ↑ 3.0 3.1 "NGC 251". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+251.
- ↑ "Distance Results for NGC 251". NASA. https://ned.ipac.caltech.edu/cgi-bin/nDistance?name=NGC+251.
- ↑ Seligman, Courtney. "New General Catalogue Objects: NGC 251". https://cseligman.com/text/atlas/ngc2a.htm#251.
- ↑ Karachentsev, I. D. (1972). "Catalogue of isolated pairs of galaxies in the northern hemisphere". Soobshcheniya Spetsial'noj Astrofizicheskoj Observatorii 7: 1-92. Bibcode: 1972SoSAO...7....1K.
- ↑ "SN 2023rky". IAU. https://www.wis-tns.org/object/2023rky.
External links
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