Photographing the Crescent Nebula

This is the Crescent Nebula (NGC 6888, C27), an emission Nebula about 5000 light years from Earth In the constellation of Cygnus, as photographed from my pool deck over four nights during November, 2022. The photograph was taken with a Celestron Edge HD11 Schmidt Cassegrain telescope by a ZWO ASI 1600mm Pro Mono Chrome camera, all riding on an iOptron CEM 60 center equatorial mount. I used a .7x focal reducer to bring the native focal length of 2800mm down to 1960mm and provide undistorted stars all the way to the edges. Since I was shooting in monochrome, I used light filters to separate the collected signal into wavelength groups so I could assign proper color.

The photograph is a compilation of 72 individual 10-minute exposures for a total exposure of 12 hours. Each picture was exposed for 10 minutes while tracking the Crescent Nebula across the sky. I took 37 images through a Ha filter and 35 images through an Oiii filter.

The Crescent Nebula is formed by a giant Wolf-Rayet Star (WR 136) that is shedding its outer layers and then radiating the debris and shaping it with strong stellar winds. WR 136 is nearing the end of its life and will soon end in a massive Supernova. This star is clearly visible in the image. It is the bright star right in the center of the nebula.

[charlottepowell]

Interesting and Beautiful, as always!Good job.