Astronomy:NGC 247

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Short description: Galaxy in the constellation Cetus
NGC 247
Wide Field Imager view of the spiral galaxy NGC 247.jpg
Image taken by the Wide Field Imager (WFI) at ESO's La Silla Observatory in Chile
Observation data (J2000 epoch)
ConstellationCetus
Right ascension 00h 47m 08.5s[1]
Declination−20° 45′ 37″[1]
Distance11.1 ± 1.2 Mly
Apparent magnitude (V)9.9[1]
Characteristics
TypeSAB(s)d[1]
Apparent size (V)21.4 × 6.9[1] (70,000 light-years in diameter)
Other designations
HIPASS J0047-20, LEDA 2758, ESO-LV 540-0220, IRAS F00446-2101, 2MASX J00470855-2045374, ESO 540-22, IRAS 00446-2101, MCG-04-03-005, GLXY G113.8-83.5+144, KUG 0044-210, UGCA 11, PGC 2758,[1] Caldwell 62
Center of NGC 247 taken by Hubble Space Telescope.[2]

NGC 247 (also known as Caldwell 62 and commonly known as the Claw Galaxy[3]) is an intermediate spiral galaxy (although it is sometimes classified as a dwarf spiral galaxy) about 11.1 Mly away in the constellation Cetus. This distance was confirmed in late February 2011. Previous measurements showed that the galaxy was about 12.2 Mly away, but this was proved to be wrong.[4] NGC 247 is a member of the Sculptor Group, and is 70 000 light years in diameter. [5]

NGC 247 has an unusually large void on one side of its spiral disk. This void contains some older, redder stars but no younger, bluer stars.[6]

Nearby galaxies and galaxy group information

NGC 247 is one of several galaxies that is gravitationally bound to the Sculptor Galaxy (NGC 253). These galaxies form a small core in the center of the Sculptor Group, which is one of the nearest groups of galaxies to the Milky Way.[7] Most other galaxies associated with the Sculptor Group are only weakly gravitationally bound to this core.[7][8]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 "NASA/IPAC Extragalactic Database". Results for NGC 247. http://nedwww.ipac.caltech.edu/. 
  2. "The centre of NGC 247". https://www.spacetelescope.org/images/potw1640a/. 
  3. Chadwick, Stephen; Cooper, Ian (11 December 2012). Imaging the Southern Sky. Springer. p. 328. ISBN 978-1461447498. 
  4. ""eso1107 — Photo Release: The Dusty Disc of NGC 247"". http://www.eso.org/public/news/eso1107/. [1]
  5. "NGC 247, an intermediate spiral galaxy in Cetus" (in nl-NL). 2013-12-05. http://annesastronomynews.com/photo-gallery-ii/galaxies-clusters/ngc-247/. 
  6. Wagner-Kaiser, R.; Demaio, T.; Sarajedini, A.; Chakrabarti, S. (2014). "The Void in the Sculptor Group Spiral Galaxy NGC 247". Monthly Notices of the Royal Astronomical Society 443 (4): 3260–3269. doi:10.1093/mnras/stu1327. Bibcode2014MNRAS.443.3260W. 
  7. 7.0 7.1 Karachentsev, I. D. (2005). "The Local Group and Other Neighboring Galaxy Groups". Astronomical Journal 129 (1): 178–188. doi:10.1086/426368. Bibcode2005AJ....129..178K. 
  8. Karachentsev, I. D.; Grebel, E. K.; Sharina, M. E.; Dolphin, A. E.; Geisler, D.; Guhathakrta, P.; Hodge, P. W.; Karachentseva, V. E. et al. (2003). "Distances to nearby galaxies in Sculptor". Astronomy and Astrophysics 404 (1): 93–111. doi:10.1051/0004-6361:20030170. Bibcode2003A&A...404...93K. 

External links

Coordinates: Sky map 00h 47m 08.5s, −20° 45′ 37″