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.
| Emission nebula | |
|---|---|
| Planetary nebula | |
 NGC 2440, as taken by the Hubble Space Telescope | |
| Observation data: J2000 epoch | |
| Right ascension | 07h 41m 54.91s[1] |
| Declination | −18° 12′ 29.7″[1] |
| Distance | 4.00 kly (1.23 kpc)[2] ly |
| Apparent magnitude (V) | 9.4[3] |
| Apparent dimensions (V) | 74" × 42"[3] |
| Constellation | Puppis |
| Physical characteristics | |
| Radius | 0.72 ly |
| Designations | ESO 560-PN9, Bow Nebula |
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
editThe 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
edit- ^ a b c (SIMBAD 2007)
- ^ a b c (Nemiroff & Bonnell 2007)
- ^ a b c (O'Meara 2007)
- ^ a b (James & Marion 2006)
- ^ "Observing at Skyhound: NGC 2440".
References
edit- SIMBAD (January 9, 2007), Results for NGC 2440, SIMBAD, Centre de Données Astronomiques de Strasbourg
- Nemiroff, R.; Bonnell, J., eds. (February 15, 2007). "Planetary Nebula NGC 2440". Astronomy Picture of the Day. NASA.
- James, Renée; Marion, Howie (April 2006), "X-treme Stars of the cosmos", Astronomy, 34 (4): 34–39, Bibcode:2006Ast....34d..34J
- O'Meara, Stephen James (2007), "Albino Butterfly, Kiss Nebula, Little Lips Nebula: NGC 2440", Hidden Treasures: 204–208
External links
edit
- Hubble Space Telescope reveals NGC 2440 on YouTube
- NASA Astronomy Picture of the Day: Planetary Nebula NGC 2440 (15 February 2007)
- NASA Astronomy Picture of the Day: NGC 2440: Cocoon of a New White Dwarf (7 May 2006)
- NASA Astronomy Picture of the Day: NGC 2440 Nucleus: The Hottest Star? (30 November 1995)
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