Eskimo Nebula

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Eskimo Nebula
NGC 2392, the Eskimo Nebula by HST.
Observation data: J2000 epoch
Right ascension 07h 29m 10.7669s[1]
Declination +20° 54′ 42.488″[1]
Distance ≥2,870 ly (≥880 pc)[2] ly
Apparent magnitude (V) 10.1[1]
Apparent dimensions (V) 48″; × 48″;[2]
Constellation Gemini
Physical characteristics
Radius ≥0.34 ly[a] ly
Absolute magnitude (V) ≤0.4 [b]
Notable features
Designations NGC 2392,[1] Caldwell 39, Clown Nebula,[1] Clown Face[1]
See also: Lists of nebulae

The Eskimo Nebula (NGC 2392), also known as the Clownface Nebula[3] or Caldwell 39, is a bipolar[4] double-shell[5] planetary nebula (PN). It was discovered by astronomer William Herschel in 1787. The formation resembles a person's head surrounded by a parka hood. It is surrounded by gas that composed the outer layers of a Sun-like star. The visible inner filaments are ejected by a strong wind of particles from the central star. The outer disk contains unusual light-year-long filaments.

Eskimo Nebula in 32 inch telescope

NGC 2392 lies more than 2,870 light-years away and is visible with a small telescope in the constellation of Gemini.

Historic data[edit]

The nebula was discovered by William Herschel on January 17, 1787, in Slough, England. He described it as "A star 9th magnitude with a pretty bright middle, nebulosity equally dispersed all around. A very remarkable phenomenon."[6] NGC 2392 WH IV-45 is included in the Astronomical League's Herschel 400 observing program.

See also[edit]


  1. ^ Radius = distance × sin(angular size / 2) = ≥2900 ly * sin(48″ / 2) = ≥0.34 ly
  2. ^ 10.1 apparent magnitude - 5 * (log10(≥880 pc distance) - 1) = ≤0.4 absolute magnitude


  1. ^ a b c d e f "NGC 2392". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-12-22. 
  2. ^ a b O'Dell, C. R.; Balick, B.; Hajian, A. R.; Henney, W. J.; et al. (2002). "Knots in Nearby Planetary Nebulae". The Astronomical Journal. 123 (6): 3329–3347. Bibcode:2002AJ....123.3329O. doi:10.1086/340726. 
  3. ^ Windows to the Universe
  4. ^ O'dell, C. R.; Balick, B.; Hajian, A. R.; Henney, W. J.; et al. (2003). "Knots in Planetary Nebulae". In S. J. Arthur & W. J. Henney. Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias). Winds, Bubbles, and Explosions: a conference to honor John Dyson, Pátzcuaro, Michoacán, México, September 9–13, 2002. 15. pp. 29–33. Bibcode:2003RMxAC..15...29O. 
  5. ^ Guerrero, M. A.; Chu, Y.-H.; Gruendl, R. A.; Meixner, M. (2005). "XMM-Newton detection of hot gas in the Eskimo Nebula: Shocked stellar wind or collimated outflows?". Astronomy and Astrophysics. 430 (3): L69–L72. arXiv:astro-ph/0412540Freely accessible. Bibcode:2005A&A...430L..69G. doi:10.1051/0004-6361:200400131. 
  6. ^ The Scientific Papers of Sir William Herschel by J. L. E. Dreyer, Royal Society, London 1912

External links[edit]

Coordinates: Sky map 07h 29m 10.7669s, +20° 54′ 42.488″