The Eskimo Nebula (NGC 2392), also known as the Clownface Nebula[4] or Caldwell 39, is a bipolar[2] 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.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.

Historic dataEdit

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 alsoEdit


  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. The Scientific Papers of Sir William Herschel by J. L. E. Dreyer, Royal Society, London 1912

External linksEdit

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