The Crescent Nebula, also designated as NGC 6888, Caldwell 27, and Sharpless 105, is an emission nebula situated in the Cygnus constellation, approximately 5,000 light-years from Earth. Discovered by William Herschel in 1792, this nebula is created by the interaction between the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) and the slower wind previously expelled when the star transitioned into a red giant around 250,000 to 400,000 years ago. This interaction produces a shell structure and generates two shock waves: one propagating outward and the other inward. The inward shock wave heats the stellar wind to temperatures that emit X-rays.

Object: NGC 6888

Location: Portsmouth, UK

Mount: EQ Mode

Bortle Scale: 7

Total Session Time: 1  Hour

Nights:       21 June 2024

Total Subs Used: 822 x 10 Subs

Seeing:  Clear, 95% Moon

Fits Stacked: Siril 

Post-Processing Steps

1. GraXpert - Background extraction and Denoise v2.0 

2. Siril - color calibration, photometric color calibration,remove green noise, color calibration, histogram stretch, colour saturation, star removal script x 1.