|Right ascension||07h 29m 10.7669s|
|Declination||+20° 54′ 42.488″|
|Distance||≥2,870 ly (≥880 pc)|
|Apparent magnitude (V)||10.1|
|Apparent dimensions (V)||48″ × 48″|
|Absolute magnitude (V)||≤0.4 [b]|
|Other designations||NGC 2392, Caldwell 39, Clown Nebula, Clown Face|
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.
- Historic data 1
- See also 2
- Notes 3
- References 4
- External links 5
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.
- 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.
- 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?".
- 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
- Eskimo Nebula at Constellation Guide