NGC 2440 is a planetary nebula, one of many in our galaxy. Its central star, HD 62166,[1] is possibly the hottest known white dwarf, about 400,000°F(200,000°C). The nebula is situated in the constellation Puppis.

NGC 2440
Emission nebula
Planetary nebula
NGC 2440, as taken by the Hubble Space Telescope
Observation data: J2000 epoch
Right ascension07h 41m 54.91s[1]
Declination−18° 12′ 29.7″[1]
Distance4.00 kly (1.23 kpc)[2] ly
Apparent magnitude (V)9.4[3]
Apparent dimensions (V)74" × 42"[3]
ConstellationPuppis
Physical characteristics
Radius0.72 ly
DesignationsESO 560-PN9, Bow Nebula
See also: Lists of nebulae
Centre of NGC 2440

It was discovered by William Herschel on March 4, 1790. He described it as "a beautiful planetary nebula of a considerable degree of brightness, not very well defined."[3] The nebula is located about 1.23 kiloparsecs (3.79×1019 m) or about 4,000 light years from the Sun.[2]

HD 62166

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The central star HD 62166 has an exceptionally high surface temperature of about 200,000 kelvins[2] and a luminosity 1,100 times that of the Sun.[4] This dense star, with an estimated 0.6 solar mass and 0.028 solar radius,[4] has an apparent magnitude of 17.5.[5]

Notes

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  1. ^ a b c (SIMBAD 2007)
  2. ^ a b c (Nemiroff & Bonnell 2007)
  3. ^ a b c (O'Meara 2007)
  4. ^ a b (James & Marion 2006)
  5. ^ "Observing at Skyhound: NGC 2440".

References

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