NGC 6934

In today's world, NGC 6934 has become a topic of relevance and discussion in society. Over time, NGC 6934 has gained importance and has caused a change in the way people perceive and approach this topic. As society advances, NGC 6934 has become increasingly relevant in different areas, generating debates, divergent opinions and, in some cases, concrete actions. Throughout history, NGC 6934 has impacted people's lives in various ways and its influence continues to be notable today. This article will explore various perspectives and approaches on NGC 6934, with the aim of analyzing its impact and scope in contemporary society.

NGC 6934
NGC 6934 by Hubble Space Telescope; 3.5′ view
Observation data (J2000 epoch)
ClassVIII[1]
ConstellationDelphinus
Right ascension20h 34m 11.37s[2]
Declination+07° 24′ 16.1″[2]
Distance52 kly (16 kpc)[3]
Apparent magnitude (V)8.83[4]
Apparent dimensions (V)1.20′[5]
Physical characteristics
Absolute magnitude−7.65[6]
Mass2.95×105[7] M☉
Metallicity = –1.47[7] dex
Other designationsCaldwell 47, NGC 6934[8]
See also: Globular cluster, List of globular clusters

NGC 6934 (also known as Caldwell 47) is a globular cluster of stars in the northern constellation of Delphinus, about 52 kilolight-years distant from the Sun.[3] It was discovered by the German-born astronomer William Herschel on 24 September 1785.[4] The cluster is following a highly eccentric orbit (with an eccentricity of 0.81) through the Milky Way along an orbital plane that is inclined by 73° to the galactic plane. It may share a common dynamic origin with NGC 5466.[6] As of 2018, it has been poorly studied.[9]

This appears to be a Oosterhoff type I cluster with an intermediate metallicity.[10] It has an Shapley–Sawyer Concentration Class of VIII,[1] with a core radius of 15″[3] and a half-light radius of 36″.[5] The estimated mass is 295,000 times the mass of the Sun.[7] The cluster displays photometric anomalies, with a split subgiant branch on the HR diagram.[9] Searches for variable stars have discovered 85 in the cluster field, of which 79 are of the RR Lyrae class and one is a SX Phe variable.[10] There is some evidence for a tidal tail.[11]

References

  1. ^ a b Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
  2. ^ a b Goldsbury, Ryan; et al. (December 2010). "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters". The Astronomical Journal. 140 (6): 1830–1837. arXiv:1008.2755. Bibcode:2010AJ....140.1830G. doi:10.1088/0004-6256/140/6/1830. S2CID 119183070.
  3. ^ a b c Hessels, J. W. T.; et al. (November 2007), "A 1.4 GHz Arecibo Survey for Pulsars in Globular Clusters", The Astrophysical Journal, 670 (1): 363–378, arXiv:0707.1602, Bibcode:2007ApJ...670..363H, doi:10.1086/521780, S2CID 16914232.
  4. ^ a b NGC 6934, SEDS, retrieved 2010-10-09
  5. ^ a b Forbes, Duncan A.; et al. (October 2008). "Uniting old stellar systems: from globular clusters to giant ellipticals". Monthly Notices of the Royal Astronomical Society. 389 (4): 1924–1936. arXiv:0806.1090. Bibcode:2008MNRAS.389.1924F. doi:10.1111/j.1365-2966.2008.13739.x. S2CID 14108457.
  6. ^ a b Dinescu, Dana I.; et al. (October 2001). "Orbits of Globular Clusters in the Outer Galaxy: NGC 7006". The Astronomical Journal. 122 (4): 1916–1927. arXiv:astro-ph/0106259. Bibcode:2001AJ....122.1916D. doi:10.1086/323094. S2CID 1232455.
  7. ^ a b c Boyles, J.; et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal, 742 (1): 51, arXiv:1108.4402, Bibcode:2011ApJ...742...51B, doi:10.1088/0004-637X/742/1/51, S2CID 118649860.
  8. ^ "NGC 6934". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-10-08.
  9. ^ a b Marino, A. F.; et al. (June 2018). "Metallicity Variations in the Type II Globular Cluster NGC 6934". The Astrophysical Journal. 859 (2): 20. arXiv:1804.04158. Bibcode:2018ApJ...859...81M. doi:10.3847/1538-4357/aabdea. S2CID 119461759. 81.
  10. ^ a b Kaluzny, J.; et al. (March 2001). "Image-Subtraction Photometry of Variable Stars in the Field of the Globular Cluster NGC 6934". The Astronomical Journal. 121 (3): 1533–1550. arXiv:astro-ph/0010303. Bibcode:2001AJ....121.1533K. doi:10.1086/319411. S2CID 14431121.
  11. ^ Wilhelm, R.; et al. (December 2002). "Does NGC 6934 Have a Tidal Tail?". Bulletin of the American Astronomical Society. 34: 1101. Bibcode:2002AAS...201.0702W.