Category: Deep Sky

Friday night I went up to the River Ridge Observatory to image some objects. I decided to start with the Iris Nebula (NGC 7023) in Cepheus which I have attempted twice before. This time I was able to take longer subs that were later combined. Each was 5 minutes long and I also lowered my gain from 300 to 200 because this object has a lot of dynamic range and I didn’t want to lose that. This was taken with my C11 and Hyperstar shooting at f/1.9 with a light pollution filter. In all 20 5 minute images were combined and all processing was done in Photoshop. I think I’ve finally gotten the three dimensional image I’ve been looking for, the nebula seems to float above the stars.

After finishing with the Crescent Nebula I moved to the Tulip Nebula. Sharpless 101 (Sh2-101) is a H II region[1] emission nebula located in the constellation Cygnus. It is sometimes also called the Tulip Nebula because it appears to resemble the outline of a tulip when imaged photographically. It was catalogued by astronomer Stewart Sharpless in his 1959 catalog of nebulae. It lies at a distance of about 6,000 light-years (5.7×1016 km; 3.5×1016 mi) from Earth.

After shooting NGC 6820, I moved to the nearby Crescent Nebula. All the settings were the same so I was able to apply the same darks and flats. The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It was discovered by William Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.