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Sextans Dwarf Spheroidal

Sextans Dwarf Spheroidal
Observation data (J2000 epoch)
ConstellationSextans
Right ascension10h 13m 02.9s[1]
Declination−01° 36′ 53″[1]
Redshift224 ± 2 km/s[1]
Distance290 ± 30 kly (90 ± 10 kpc)[2][3]
Apparent magnitude (V)10.4[1]
Characteristics
TypedSph[1]
Apparent size (V)30.0′ × 12.0′[1]
Notable featuressatellite galaxy of the Milky Way
Other designations
Sextans I,[1] LEDA 88608[1]

The Sextans Dwarf Spheroidal is a dwarf spheroidal galaxy that was discovered in 1990 by Mike Irwin as the 8th satellite of the Milky Way,[4] located in the constellation of Sextans. It is also an elliptical galaxy, and displays a redshift because it is receding from the Sun at 224 km/s (72 km/s from the Galaxy). The distance to the galaxy is 320,000 light-years and the diameter is 8,400 light-years along its major axis.[5]

Like other dwarf spheroidal galaxies, the Sextans Dwarf's population consists of old, metal-poor stars: one study found that the majority of stars have a metallicity between [Fe/H] = −3.2 and −1.4. An analysis of several stars found them to also be deficient in barium, except for one star.[6]

References

  1. ^ a b c d e f g h "NASA/IPAC Extragalactic Database". Results for Sextans Dwarf. Retrieved 2006-11-29.
  2. ^ I. D. Karachentsev; V. E. Karachentseva; W. K. Hutchmeier; D. I. Makarov (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal. 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi:10.1086/382905.
  3. ^ Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics. 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. S2CID 120973010.
  4. ^ M. J. Irwin; P. S. Bunclark; M. T. Bridgeland; R. G. McMahon (1990). "A new satellite galaxy of the Milky Way in the constellation of Sextans". Monthly Notices of the Royal Astronomical Society. 244: 16–19. Bibcode:1990MNRAS.244P..16I.
  5. ^ Hartmut Frommert. "Sextans Dwarf". SEDS. Retrieved 2015-03-21.
  6. ^ Mashonkina, L.; Pakhomov, Yu V.; Sitnova, T.; Jablonka, P.; Yakovleva, S. A.; Belyaev, A. K. (2022). "The formation of the Milky Way halo and its dwarf satellites: A NLTE–1D abundance analysis. V. The Sextans galaxy". Monthly Notices of the Royal Astronomical Society. 509 (3): 3626–3642. arXiv:2110.09402. doi:10.1093/mnras/stab3189.


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