Eskimo Nebula

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NGC 2392
Emission nebula
Planetary nebula
Ngc2392.jpg
NGC 2392, the Eskimo Nebula by HST in 1999.
Observation data: J2000 epoch
Right ascension07h 29m 10.7669s[1]
Declination+20° 54′ 42.488″[1]
Distance6520±560[2] ly
Apparent magnitude (V)10.1[1]
Apparent dimensions (V)48″; × 48″;[3]
ConstellationGemini
Physical characteristics
Radius≥0.34 ly[a] ly
Absolute magnitude (V)≤0.4 [b]
Notable features
DesignationsNGC 2392,[1] Caldwell 39, PN G197.8+17.3
Central Star: HIP 36369, HD 59088, TYC 1372-1287-1
See also: Lists of nebulae

The Eskimo Nebula (NGC 2392), also known as the Clown-faced Nebula, Lion Nebula,[4] or Caldwell 39, is a bipolar[5] double-shell[6] 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 with a spectral type of O(H)6f.[7]

Historic data[edit]

NGC 2392 in 32 inch telescope

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."[8] NGC 2392 WH IV-45 is included in the Astronomical League's Herschel 400 observing program.

Location[edit]

align=left

NGC 2392 is located just east of δ Geminorum, just south the ecliptic.

Naming controversy[edit]

On 11 August 2020, the IAU Working Group on Star Names (WGSN),[citation needed] NASA/IPAC Extragalactic Database (NED),[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.[9][1]

See also[edit]

Notes[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

References[edit]

  1. ^ a b c d e "NGC 2392". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-12-22.
  2. ^ Gaia Collaboration et al. (2018b): Summary of the contents and survey properties
  3. ^ 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.
  4. ^ Deep-Sky Companions: The Caldwell Objects, 2nd Edition, Stephen James O'Meara, 2016, p.181
  5. ^ 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 (ed.). 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. Vol. 15. pp. 29–33. Bibcode:2003RMxAC..15...29O.
  6. ^ 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.
  7. ^ González-Santamaría, I.; Manteiga, M.; Manchado, A.; Ulla, A.; Dafonte, C.; López Varela, P. (2021). "Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity". Astronomy & Astrophysics. 656: A51. arXiv:2109.12114. Bibcode:2021A&A...656A..51G. doi:10.1051/0004-6361/202141916. S2CID 237940344.
  8. ^ The Scientific Papers of Sir William Herschel by J. L. E. Dreyer, Royal Society, London 1912
  9. ^ Talbert, Tricia (11 August 2020). "NASA to Reexamine Nicknames for Cosmic Objects". NASA. Retrieved 11 August 2020.

External links[edit]

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