Astronomy:NGC 2232

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NGC 2232
NGC 2232.png
NGC 2232 (taken from Stellarium)
Observation data (J2000 epoch)
Right ascension 06h 27m 15s[1]
Declination–04° 45′ 30″[1]
Distance1,060 ly (325 pc)[2]
Apparent magnitude (V)3.9[3]
Apparent dimensions (V)30′ [3]
Physical characteristics
Mass< 100[4] M
Radius~15 ly[4]
Estimated age30.9 Myr[2]
Other designationsCr 93, C 0624-047[5]
See also: Open cluster, List of open clusters
Map showing the location of NGC 2232

NGC 2232 is a bright open star cluster in the equatorial constellation of Monoceros, centered on the star 10 Monocerotis.[3] It is located in the Gould Belt close to the Orion Nebula cluster,[6] at a mean distance of 1,060 ly from the Sun.[2] The average radial velocity of the cluster members is 26.6±0.77 km/s.[7] This is one of the nearest open clusters to the Sun, which makes it a potentially useful target for studying young stars and their transition to the main sequence.[8]

The cluster has an angular radius of 36 and a core angular radius of 7.2′. It is a sparse cluster with twenty high–probability members.[2] This is considered a super-solar cluster, with the components generally having a higher abundance of iron compared to the Sun. The mean metallicity is 0.22±0.09 or 0.32±0.08, depending on what assumptions are made.[7] At least four cluster members display an infrared excess at a wavelength of 8μm that is suggestive of warm dust, while the A-type star HD 45435 displays a strong excess at 24μm. The latter may indicate the star is in an early evolutionary state.[6] Only one member of the cluster appears to be chemically peculiar.[9]


  1. 1.0 1.1 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, doi:10.1111/j.1365-2966.2009.15416.x, Bibcode2009MNRAS.399.2146W. 
  2. 2.0 2.1 2.2 2.3 Kharchenko, N. V. et al. (2005), "Astrophysical parameters of Galactic open clusters", Astronomy and Astrophysics 438 (3): 1163, doi:10.1051/0004-6361:20042523, Bibcode2005A&A...438.1163K. 
  3. 3.0 3.1 3.2 Dunlop, Storm (2005). Atlas of the Night Sky. Collins. ISBN 978-0-00-717223-8. 
  4. 4.0 4.1 Finlay, Warren H. (2014), Concise Catalog of Deep-sky Objects, The Patrick Moore Practical Astronomy Series (2nd ed.), Springer Science & Business Media, p. 188, ISBN 978-3-319-03169-9. 
  5. "NGC 2232". SIMBAD. Centre de données astronomiques de Strasbourg. 
  6. 6.0 6.1 Currie, Thayne et al. (November 2008), "A Spitzer Study of Debris Disks in the Young Nearby Cluster NGC 2232: Icy Planets Are Common around ~1.5-3 M☉ Stars", The Astrophysical Journal 688 (1): 597–615, doi:10.1086/591842, Bibcode2008ApJ...688..597C. 
  7. 7.0 7.1 Monroe, TalaWanda R.; Pilachowski, Catherine A. (December 2010), "Metallicities of Young Open Clusters. I. NGC 7160 and NGC 2232", The Astronomical Journal 140 (6): 2109–2123, doi:10.1088/0004-6256/140/6/2109, Bibcode2010AJ....140.2109M. 
  8. Orban, Chris; Patten, Brian (January 1, 2004), Late-Type Membership of the Open Cluster NGC 2232, Greenbelt, MD, United States: NASA Goddard Space Flight Center,, retrieved 2020-04-13. 
  9. Jenkner, H.; Maitzen, H. M. (November 1987), "Photoelectric search for CP2-stars in open clusters. X. NGC 2232, NGC2343, CR 140, and TR 10.", Astronomy and Astrophysics, Supplemental Series 71: 255–261, Bibcode1987A&AS...71..255J. 

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