NGC 7492

NGC 7492
NGC 7492 with legacy surveys
Observation data (J2000 epoch)
ClassXII
ConstellationAquarius
Right ascension23h 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 = -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. ^ a b c "NGC 7492". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-09-30.
  2. ^ a b 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
  4. ^ ULTRAVIOLET PROPERTIES OF GALACTIC GLOBULAR CLUSTERS WITH GALEX. II. INTEGRATED COLORS
  5. ^ Seligman, Courtney. "New General Catalogue objects: NGC 7450 - 7499". cseligman.com. 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, arXiv:1907.02071, Bibcode:2019A&A...627A..70K, doi:10.1051/0004-6361/201935467, S2CID 195798995
  7. ^ 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, arXiv:1705.04324, Bibcode:2017ApJ...841L..23N, doi:10.3847/2041-8213/aa72e1, S2CID 59384819
  9. ^ Sollima, A.; Martínez Delgado, D.; Muñoz, R. R.; Carballo-Bello, J. A.; Valls-Gabaud, D.; Grebel, E. K.; Santana, F. A.; Côté, P.; Djorgovski, S. G. (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, arXiv:1802.09255, doi:10.1093/mnras/sty539
  10. ^ MASS SEGREGATION AND TIDAL TAILS OF THE GLOBULAR CLUSTER NGC 7492