Astronomy:NGC 6638

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Short description: Globular cluster in the constellation Sagittarius
NGC 6638
NGC6638 - HST - Potw2231a.jpg
Observation data (J2000 epoch)
ClassVI
ConstellationSagittarius
Right ascension 18h 30m 56.2s
Declination−25° 29′ 45″
Distance31.3 ± 1.6 kly (9.6 ± 0.5 kpc)[1]
Apparent magnitude (V)9.5
Apparent dimensions (V)2′
Physical characteristics
Mass1.89×105[1] M
Other designationsGCl 95, C 1827-255[2]
See also: Globular cluster, List of globular clusters

NGC 6638 is a globular cluster in the constellation Sagittarius. It is magnitude 9.5 and diameter 2 arc minutes, class VI. It is a half degree east of Lambda Sagittarii. It is a member of the Milky Way.[3]

The globular cluster was discovered in 1784 by the astronomer William Herschel with his 18.7-inch telescope and the discovery was later entered in the New General Catalogue.

References

  1. 1.0 1.1 Oliveira, R. A. P.; Ortolani, S.; Barbuy, B.; Kerber, L. O.; Maia, F. F. S.; Bica, E.; Cassisi, S.; Souza, S. O. et al. (2022). "Precise distances from OGLE-IV member RR Lyrae stars in six bulge globular clusters". Astronomy & Astrophysics 657: A123. doi:10.1051/0004-6361/202141596. Bibcode2022A&A...657A.123O. 
  2. "NGC 6638". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+6638. 
  3. Harris, W.E. (1996). "A Catalog of Parameters for Globular Clusters in the Milky Way". The Astronomical Journal 112: 1487. doi:10.1086/118116. Bibcode1996AJ....112.1487H. http://physwww.physics.mcmaster.ca/%7Eharris/mwgc.dat. 
  • Robert Burnham, Jr, Burnham's Celestial Handbook: An observer's guide to the universe beyond the solar system, vol 3, p. 1557

External links