NGC 185

Dwarf Spheroidal Galaxy NGC 185, type dE3 pec, in Cassiopeia

[NGC 185, JKT/ING]

00 : 39.0
+84 : 20
dE3 pec
+ 39 km/s
2300 kly
Apparent Dimension:
14.5 x 12.5 arc min
9700 ly
9.2 m_vis
Abs. Mag:
- 15.8 Mag vis
This galaxy was discovered (as a "Faint Nebula") by William Herschel on November 30, 1787, and cataloged by him as H II.707. His son John Herschel observed it again and cataloged it as h 35 in his catalog of 1833, and as GC 90 in his General Catalogue of 1864. They described it as follows: A first photograph of NGC 185 was obtained by James Edward Keeler with the Crossley Reflector of Lick Observatory between 1898 and 1900.

NGC 185 was recognized as a Local Group member galaxy, together with its neighbor NGC 147, by Walter Baade (1944), when he resolved them into stars with the 100-inch reflector on Mt. Wilson. These two dwarf elliptical galaxies apparently form a physical pair, as they are only 58 arc minutes separated; according to Van den Bergh, they are probably gravitationally bound in a physical pair. Both are more remote satellite galaxies of the Andromeda Galaxy M31, but are at a somewhat closer distance to us these times. Modern distance estimates for NGC 185, adjusted for the scale we use here, correspond to some 2.3 million light-years.

The image in this page was obtained by astronomers of the Isaac Newton Group of Telescopes on La Palma, under the leadership of D. Martínez-Delgado, in 1999. It is a combination of B, V, and R images from the Jacobus Kapteyn Telescope. From this image, evidence was found that NGC 185 actually contains young stellar clusters, which had been thought to be luminous, blue stars, by their discoverer Walter Baade. According to research of these images, star formation proceeded at a low rate until the recent past, the age of the most recent traces of star formation activity detected in the galaxy being some 100 million years. These conclusions rule out the possibility of NGC 185 being an old galaxy formed by Population II stars only.

  • IAC Press Release of 21 December 1999 [local archival copy]
  • Hi-res (1000x1000 pixel) version of this image



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    Hartmut Frommert
    Christine Kronberg

    Last Modification: December 5, 2005