Pegasus Dwarf Spheroidal Galaxy Explained

Pegasus Dwarf Spheroidal Galaxy
Type:	dSph
Epoch:	J2000
Ra:	^[1]
Dist Ly:	2.7 ± 0.1 Mly (820 ± 20 kpc)^[2]
Z:	−354 ± 3 km/s
Appmag V:	14.2
Size V:	4.0 × 2.0
Constellation Name:	Pegasus
Notes:	-
Names:	Pegasus II, Andromeda VI, Peg dSph, KKH 99, PGC 2807158

The Pegasus Dwarf Spheroidal (also known as Andromeda VI or Peg dSph for short) is a dwarf spheroidal galaxy about 2.7 million light-years away in the constellation Pegasus. The Pegasus Dwarf is a member of the Local Group and a satellite galaxy of the Andromeda Galaxy (M31).

General information

The Pegasus Dwarf Spheroidal is a galaxy with mainly metal-poor stellar populations.^[3] Its metallicity is [Fe/H] ≃ −1.3.^[4] It is located at the right ascension 23h51m46.30s and declination +24d34m57.0s in the equatorial coordinate system (epoch J2000.0), and in a distance of 820 ± 20 kpc from Earth and a distance of 294 ± 8 kpc from the Andromeda Galaxy.

The galaxy was discovered in 1999^[5] by various authors on the Second Palomar Observatory Sky Survey (POSS II) films.^[6]

See also

• List of Andromeda's satellite galaxies
• Pegasus Dwarf Irregular Galaxy (Peg DIG)
• Pegasus galaxy, the Stargate Atlantis fictional location (probably the Pegasus Dwarf Irregular Galaxy).

Notes

1. For an angular distance θ between C andG, their mutual linear distance R is given by:
         R² = D + D - 2 × D_g × D_c × cos(θ)^[7]

External links

• NASA/IPAC Extragalactic Database: Pegasus Dwarf Spheroidal
• Armandroff, Jacoby, & Davies, "Low Surface Brightness Galaxies around M31", Astrophys. J. 118, 1220-1229 (1999).

Notes and References

1. Web site: NASA/IPAC Extragalactic Database . Results for Pegasus Dwarf Spheroidal . 2006-11-11.
2. I. D. Karachentsev . V. E. Karachentseva . W. K. Hutchmeier . D. I. Makarov . A Catalog of Neighboring Galaxies . Astronomical Journal . 2004 . 127 . 4 . 2031–2068 . 2004AJ....127.2031K . 10.1086/382905. free .
3. Book: Van den Bergh, Sidney . May 15, 2000 . The Galaxies of the Local Group . Cambridge Astrophysics . 240 . 978-1-139-42965-8.
4. McConnachie, A. W. . Irwin, M. J. . Ferguson, A. M. N. . Ibata, R. A. . Lewis, G. F. . Tanvir, N. . Distances and metallicities for 17 Local Group galaxies . . 2005 . 356 . 4 . 979–997 . 2005MNRAS.356..979M . 10.1111/j.1365-2966.2004.08514.x . free . astro-ph/0410489 .
5. 2005AJ....129.2232P . The Dwarf Spheroidal Companions to M31: Variable Stars in Andromeda I and Andromeda III . May 2005 . The Astronomical Journal . 129 . 5 . 2232 - 2256 . 10.1086/428372 . Pritzl, Barton J. . Armandroff, Taft E. . Jacoby, George H. . Da Costa, G. S. . astro-ph/0501083. 9749493 .
6. Web site: Wallace Sargent . The Second Palomar Observatory Sky Survey (POSS II) . Caltech . dead . https://web.archive.org/web/20090516193335/http://www.astro.caltech.edu/~wws/poss2.html . 2009-05-16 .
7. Karachentsev, I. D. . Kashibadze, O. G. . Masses of the local group and of the M81 group estimated from distortions in the local velocity field . Astrophysics . 2006 . 49 . 1 . 3–18 . 2006Ap.....49....3K . 10.1007/s10511-006-0002-6. 120973010 .