Astronomy:NGC 7492

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NGC 7492
NGC 7492 with legacy surveys
Observation data (J2000 epoch)
ClassXII
ConstellationAquarius
Right ascension 23h 08m 26.7s[1]
Declination−15° 36′ 39″[1]
Distance24,500 kpc (80,000×10^3 ly)[2]
Apparent magnitude (V)11.2
Apparent dimensions (V)4.2′
Physical characteristics
Absolute magnitude0.38±0.04[3]
Metallicity[Fe/H] = -1.69[4] dex
Estimated age12 Gyr[2]
Other designationsGCl 125, MWSC 3705
See also: Globular cluster, List of globular clusters

NGC 7492 is a globular cluster[1] in the constellation Aquarius. It was discovered by the astronomer William Herschel on September 20, 1786.[5] It resides in the outskirts of the Milky Way, about 80,000 light-years away, more than twice the distance between the Sun and the center of the galaxy, and is a benchmark member of the outer galactic halo.[6] The cluster is immersed in, but does not kinematically belong to, the Sagittarius Stream.[7]

NGC 7492 possess a tidal tail 3.5 degrees long,[8] embedded into an over-density of stars which may be the remnants of a disrupted dwarf galaxy.[9] The shape of the cluster is flattened rather than spherical, likely due to dynamical interaction with the Milky Way.[10]

References

  1. ↑ 1.0 1.1 1.2 "NGC 7492". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+7492. 
  2. ↑ 2.0 2.1 Kumar, Ranjan; Pradhan, Ananta; Mohapatra, Abhisek; Moharana, Ayush; Ojha, Devendra; Parthasarathy, M; Murthy, Jayant (January 6, 2021). "Ultraviolet Imaging Telescope (UVIT) observation of the Galactic globular cluster NGC 7492". Monthly Notices of the Royal Astronomical Society 502: 313–327. doi:10.1093/mnras/staa4032. https://www.researchgate.net/publication/347966159_Ultraviolet_Imaging_Telescope_UVIT_observation_of_the_Galactic_globular_cluster_NGC_7492. 
  3. ↑ "Variable stars in the globular cluster NGC 7492, New discoveries and physical parameter determination". https://www.aanda.org/articles/aa/pdf/2013/08/aa20824-12.pdf. 
  4. ↑ ULTRAVIOLET PROPERTIES OF GALACTIC GLOBULAR CLUSTERS WITH GALEX. II. INTEGRATED COLORS
  5. ↑ Seligman, Courtney. "New General Catalogue objects: NGC 7450 - 7499". http://cseligman.com/text/atlas/ngc74a.htm#7492. Retrieved 2021-10-02. 
  6. ↑ Koch, Andreas; Xu, Siyi; Rich, R. Michael (2019), "Chemical composition of the outer halo globular cluster Palomar 15", Astronomy & Astrophysics 627: A70, doi:10.1051/0004-6361/201935467, Bibcode: 2019A&A...627A..70K 
  7. ↑ Carballo-Bello, J; Corral-Santana, J.; Catelan, Márcio; Delgado, David; Muñoz, R; Sollima, A; Navarrete, Camila; Duffau, S et al. (November 23, 2017). "The globular cluster NGC 7492 and the Sagittarius tidal stream: together but unmixed". Monthly Notices of the Royal Astronomical Society 474: 4766–4771. doi:10.1093/mnras/stx3001. https://www.researchgate.net/publication/321210818_The_globular_cluster_NGC_7492_and_the_Sagittarius_tidal_stream_together_but_unmixed. 
  8. ↑ Navarrete, C.; Belokurov, V.; Koposov, S. E. (2017), "The Discovery of Tidal Tails around the Globular Cluster NGC 7492 with Pan-STARRS1", The Astrophysical Journal 841 (2): L23, doi:10.3847/2041-8213/aa72e1, Bibcode: 2017ApJ...841L..23N 
  9. ↑ Sollima, A.; Martínez Delgado, D.; Muñoz, R. R.; Carballo-Bello, J. A.; Valls-Gabaud, D.; Grebel, E. K.; Santana, F. A.; Côté, P. et al. (2018), "A survey for dwarf galaxy remnants around 14 globular clusters in the outer halo", Monthly Notices of the Royal Astronomical Society 476 (4): 4814–4829, doi:10.1093/mnras/sty539 
  10. ↑ MASS SEGREGATION AND TIDAL TAILS OF THE GLOBULAR CLUSTER NGC 7492