NGC 2440
Planetary nebula in the constellation Puppis
From Wikipedia, the free encyclopedia
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
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]
