NGC 2175

NGC 2175
Observation data (J2000 epoch)
Right ascension06h 09m 39.0s
Declination+20° 29′ 12″
Distance5,290 ly (1,621 pc)
Apparent magnitude (V)6.8
Apparent dimensions (V)18′
Physical characteristics
Estimated age9.06±0.05 Myr
Other designationsNGC 2175, Cr 84, OCL 476
Associations
ConstellationOrion
See also: Open cluster, List of open clusters

NGC 2175 is a very young open cluster of stars in the equatorial constellation of Orion. It was discovered by Italian astronomer Giovanni Batista Hodierna before 1654 and independently discovered by German astronomer Karl Christian Bruhns on February 6, 1877. NGC 2175 is at a distance of about 5,290 light years away from Earth, and it is embedded in a diffuse nebula, NGC 2174.

The estimated age of this cluster is nine million years. The nebula surrounding it is Sharpless catalog Sh 2-252, and it is sometimes called the Monkey Head Nebula due to its appearance. In 1970, a smaller star cluster designated NGC 2175s was discovered in the vicinity.

Designation

There is some equivocation in the use of the identifiers NGC 2174 and NGC 2175. These may apply to the entire nebula, to its brightest knot, or to the star cluster it includes. Burnham's Celestial Handbook lists the entire nebula as 2174/2175 and does not mention the star cluster. The NGC Project (working from the original descriptive notes) assigns NGC 2174 to the prominent knot at J2000 06h 09m 23.7s, +20° 39′ 34″ and NGC 2175 to the entire nebula, and by extension to the star cluster. Simbad uses NGC 2174 for the nebula and NGC 2175 for the star cluster.

NGC 2175, LRGBHa image with 17" PlaneWave CDK by W4SM

References

  1. 1 2 Wu, Zhen-Yu; et al. (November 2009). "The orbits of open clusters in the Galaxy". Monthly Notices of the Royal Astronomical Society. 399 (4): 2146–2164. arXiv:0909.3737. Bibcode:2009MNRAS.399.2146W. doi:10.1111/j.1365-2966.2009.15416.x. S2CID 6066790.
  2. 1 2 3 4 Loktin, A. V.; Popova, M. E. (July 2017). "Updated version of the 'homogeneous catalog of open cluster parameters'". Astrophysical Bulletin. 72 (3): 257–265. doi:10.1134/S1990341317030154. ISSN 1990-3421.
  3. 1 2 3 4 Frommert, Hartmut. "Revised NGC Data for NGC 2175". Students for the Exploration and Development of Space. Retrieved 2026-04-27.
  4. 1 2 "NGC 2175". SIMBAD. Centre de données astronomiques de Strasbourg.
  5. 1 2 Grasdalen, G. L.; Carrasco, L. (October 1975). "NGC 2175: the cluster age and the nature of the nebulosity surrounding S 252a". Astronomy and Astrophysics. Bibcode:1975A&A....43..259G.
  6. ↑ Frommert, Hartmut; Kronberg, Christine (February 1, 2002). "NGC 2175". Students for the Exploration and Development of Space. Retrieved 2026-04-27.
  7. ↑ Seligman, Courtney. "NGC 2174 (= a knot in NGC 2175)". Celestial Atlas. Retrieved 2026-04-27. See also NGC 2175.
  8. ↑ Yates, Joseph (December 29, 2013). "NGC 2175, The Monkey Head Nebula". Retrieved 2026-04-27.
  9. ↑ Pișmiș, P. (May 1970). "Studies of Star Cluster (A New Small Cluster Near NGC 2175 and some Remarks on the Latter)". Boletín de los Observatorios de Tonantzintla y Tacubaya. 5: 219–227. Bibcode:1970BOTT....5..219P.
  10. ↑ Burnham, Jr., Robert (1978). Burnham's Celestial Handbook. Dover. p. 1280.
  11. ↑ "Public Database". NGC/IC Project. Results for NGC 2174 and NGC 2175. Archived from the original on 28 May 2009. Retrieved 12 January 2014.
  12. ↑ "NGC 2174". SIMBAD. Centre de données astronomiques de Strasbourg.