The Eskimo Nebula (NGC 2392), also known as the Clownface Nebula or Caldwell 39, is a bipolar double-shell 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.NGC 2392 lies more than 2,870 light-years away and is visible with a small telescope (but more preferably with a larger telescope) in the constellation of Gemini.
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." NGC 2392 WH IV-45 is included in the Astronomical League's Herschel 400 observing program.
- ^ Radius = distance × sin(angular size / 2) = ≥2900 ly * sin(48″ / 2) = ≥0.34 ly
- ^ 10.1 apparent magnitude - 5 * (log10(≥880 pc distance) - 1) = ≤0.4 absolute magnitude
- "SIMBAD Astronomical Database". Results for Eskimo Nebula. Retrieved 2006-12-22.
- O'dell, C. R.; Balick, B.; Hajian, A. R.; Henney, W. J.; et al. (2003). "Knots in Planetary Nebulae". Winds, Bubbles, and Explosions: a conference to honor John Dyson, Pátzcuaro, Michoacán, México, September 9–13, 2002 (Eds. S. J. Arthur & W. J. Henney) Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) (http://www.astroscu.unam.mx/~rmaa/) 15: 29–33. Bibcode:2003RMxAC..15...29O. External link in |journal= (help)
- 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.
- Windows to the Universe
- 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/0412540. Bibcode:2005A&A...430L..69G. doi:10.1051/0004-6361:200400131.
- The Scientific Papers of Sir William Herschel by J. L. E. Dreyer, Royal Society, London 1912
- APOD (2003-12-07) – NGC 2392: The Eskimo Nebula
- The Eskimo Nebula on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images