NGC 4609

NGC 4609
NGC 4609 (taken from Stellarium)
Observation data (J2000 epoch)
Right ascension12h 42m 19.7s[1]
Declination−62° 59′ 42″[1]
Distance4,500 ly (1,379 pc)[1]
Apparent magnitude (V)6.9[2]
Apparent dimensions (V)6.5′.[1]
Physical characteristics
Estimated age83.2 Myr[1]
Other designationsNGC 4609, Caldwell 98, Cr 263[3]
Associations
ConstellationCrux
See also: Open cluster, List of open clusters
Map showing the location of NGC 4609

NGC 4609 (also known as Caldwell 98) is an open cluster of stars in the southern constellation of Crux. It was discovered on May 12, 1826 by the Scottish astronomer James Dunlop.[4] The cluster has an apparent visual magnitude of 6.9[2] and spans an angular size of 6.5′.[1] It is situated beyond the Coalsack Nebula[5] at an estimated distance of 4,500 ly (1,379 pc) from the Sun.[1]

This is an intermediate age cluster[6] estimated at 83.2 Myr old.[1] It is a poorly populated cluster with just one red giant member. 33 probable members have been identified,[7] including the variable Be star BZ Crucis.[8] The metallicity of the cluster, as measured by the abundance of iron, is slightly larger than in the Sun.[7]

References

  1. ^ a b c d e f g h Tarricq, Y.; et al. (March 2021), "3D kinematics and age distribution of the open cluster population", Astronomy & Astrophysics, 647, id. A19, arXiv:2012.04017, Bibcode:2021A&A...647A..19T, doi:10.1051/0004-6361/202039388.
  2. ^ a b Streicher, M. (2003), "Deep-sky dedication", Monthly Notes of the Astronomical Society of South Africa, 62: 140–145, Bibcode:2003MNSSA..62..140S.
  3. ^ "NGC 4609". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2024-04-07.
  4. ^ Seligman, Courtney, "NGC Objects: NGC 4600 - 4649", Celestial Atlas, retrieved 2024-04-07.
  5. ^ Feinstein, A.; Marraco, H. G. (April 1971), "The open cluster NGC 4609 behind the coalsack", Publications of the Astronomical Society of the Pacific, 83: 218, Bibcode:1971PASP...83..218F, doi:10.1086/129108.
  6. ^ Kook, Seung-Hwa; et al. (October 2010), "UBV i CCD Photometry of the Open Clusters NGC 4609 and HOGG 15", Journal of the Korean Astronomical Society, 43 (5): 141–152, arXiv:1009.2843, Bibcode:2010JKAS...43..141K, doi:10.5303/JKAS.2010.43.5.141.
  7. ^ a b Drazdauskas, Arnas; et al. (October 2016), "Chemical composition of evolved stars in the young open clusters NGC 4609 and NGC 5316", Monthly Notices of the Royal Astronomical Society, 462 (1): 794–803, arXiv:1608.08375, Bibcode:2016MNRAS.462..794D, doi:10.1093/mnras/stw1701.
  8. ^ Smith, Myron A.; Balona, Luis (March 2006), "The Remarkable Be Star HD 110432 (BZ Crucis)", The Astrophysical Journal, 640 (1): 491–504, arXiv:astro-ph/0509094, Bibcode:2006ApJ...640..491S, doi:10.1086/499936.