Eskimo Nebula

The Eskimo Nebula (NGC 2392), also known as the Clown Face Nebula, Lion Nebula,<ref>Deep-Sky Companions: The Caldwell Objects, 2nd Edition, Stephen James O'Meara, 2016, p.181</ref> or Caldwell 39, is a bipolar<ref name="ODelletal2003">Template:Cite conference</ref> double-shell<ref name="Guerreroetal2005">Template:Cite journal</ref> 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 about 6500 light-years away, and is visible with a small telescope in the constellation of Gemini.

At the center of NGC 2392, there is an O-type star (designated HD 59088<ref>Template:Cite journal</ref>) with a spectral type of O(H)6f.<ref>Template:Cite journal</ref>

Historic data

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."<ref>The Scientific Papers of Sir William Herschel by J. L. E. Dreyer, Royal Society, London 1912</ref> NGC 2392 WH IV-45 is included in the Astronomical League's Herschel 400 observing program.

On 9 January 1982 it was occulted by the Moon during a Total Lunar Eclipse (the January 1982 lunar eclipse) over Greenland, the Arctic, the extreme northeast of North America, the northern half of Europe, North and Northeast Asia. This event was seen by several observers in England. The occultation during total eclipse will happen again during the January 2066 lunar eclipse over the northern half of Asia and the Northwest Pacific.<ref name="Mus2002">Template:Cite book</ref>Template:Rp

Naming controversy

File:Gemini IAU.svg

Location of Eskimo Nebula in Gemini, just east of δ Geminorum (annotated as 2392)

On 11 August 2020, the IAU Working Group on Star Names (WGSN),Template:Citation needed NASA/IPAC Extragalactic Database (NED),Template:Citation needed and SIMBAD Astronomical Database (CDS) discontinued use of three nicknames that were perceived as offensive – "Eskimo Nebula", "Clown Face Nebula", and "Clownface Nebula" – and strongly recommended the nebula be referred to by its NGC designation in further publications.<ref>Template:Cite news</ref><ref name="simbad" />

See also

• List of planetary nebulae
• New General Catalogue

Notes

1. Template:Note labelRadius = distance × sin(angular size / 2) = ≥2900 ly * sin(48Template:Pprime / 2) = ≥0.34 ly
2. Template:Note label10.1 apparent magnitude – 5 * (log₁₀(≥880 pc distance) – 1) = ≤0.4 absolute magnitude

External links

• Template:WikiSky
• APOD (2003-12-07) – NGC 2392
• Eskimo Nebula Lowell Observatory
• The Structure & Evolution of the Eskimo Planetary Nebula University of Maryland Astronomy Department
• A Kinematic Determination of the Structure of the Double Ring Planetary Nebula NGC 2392, the Eskimo Astrophysical Journal v.362, p. 226 October 1990
• A Cat's Eye view of the Eskimo from Saturn Maria-Teresa Garc ́ıa-D ́ıaz, Jose-Alberto L ́opez, Wofgang Steffen, Michael G. Richer and Hortensia Riesgo, 2011