|The supernova remnant NGC 6960 (Veil nebula, Cirrus nebula) in the constellation
Cygnus on July 24/25, 2012. Discovered by the German-born British astronomer William Herschel in 1784, this cloud of heated and ionized
gas is the result of a supernova which exploded some 5000-8000 years ago. The brightest star in the image is 52 Cygni. It is a foreground
star which can be seen by the naked eye (source: Wikipedia).
Fifteen 3 minute exposures (resulting in a 45 minute exposure) at ISO 800 and 4 separate dark frames (with the same settings) were combined in DeepSkyStacker for this shot. Due to humid airmasses, the transparency was reduced significantly and the mild temperatures caused a considerable amount of noise in the image. On the other hand, the air was steady and the mirror has cooled down to air temperature - ideal conditions for pinpoint stars.
|Equipment: Canon EOS 20Da camera (DX sensor with 8 megapixels), TeleVue coma corrector, Zambuto 16" f/5 quartz optics in a Dieter Martini dobsonian telescope (the coma corrector multiplies the focal length of the parabolic mirror by 1.15, leading to a focal length of 2.3 meters), dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Teleskop-Service off axis system TS-OAG9 EOS.|