NGC 2440

NGC 2440 is the name of a planetary nebula in the constellation Puppis. NGC 2440 has an angular extent of about 1.32 arc minutes and a brightness of 9.4 mag. Its central star, a white dwarf, with nearly 200,000 K surface temperature of the hottest stars known and glows in visible light with an apparent magnitude of 17.7 mag. His absolute luminosity exceeds that of our sun by 250 times.

The ejected from this central star gas clouds show two very different regions that are obviously created in different periods: a bright inner region with two distinct brightness priorities, hence the name occasionally used insect fog, and a much fainter outer region with far greater extent. The distance of NGC 2440 to our solar system is generally estimated at 1600 light years.

Discovery

The planetary nebula NGC 2440 was discovered on March 4, 1790 by the German - British astronomer William Herschel.

Visual observation

NGC 2440 is one of the visually brighter planetary nebulae, just bright enough to scan him with a commercially available webcam to a medium-sized instrument ( image on the left ). The finding is quite simple: just under 9 ° north is the 3.9 likes bright star α Monocerotis in the unicorn. Halfway to NGC 2440, in exactly southerly direction, you will inevitably come to NGC 2438, another planetary nebula, over.

In the eyepiece of a medium-sized instrument by 8 " opening NGC 2440 shows at approximately 260 - fold magnification as small, dim and diffuse Nebelchen, which is shaped more like a gummy bear.