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).

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] 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.