Crescent Tricolour Start

3019bb21492efe5c56ea973338b60683.1824x0_q100_watermark_watermark_opacity-60_watermark_position-6_watermark_text-Copyright Patrick Gilliland 2014
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. It was discovered by Friedrich Wilhelm 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.

Imaging telescope / lens: Borg ED 101
Mount: AstroPhysics AP1200 AP1200GTO
Guide telescope / lens: Borg ED 101
Camera guide: QSI 683WSG-8 OAG QSI 683
Focal reducers: Borg Super reducer f / 4
Software: Pixinsight 1.8, Photoshop CS 6 Photoshop CS6
Filters: Astrodon OIII 5nm, Astrodon SII 5nm, Astrodon Ha 5nm
Accessories: Starlight Xpress lodestar Lodestar
Resolution: 3172×2287
Dates: November 23, 2014
Astrodon Ha 5nm: 4×1800 “-20C bin 1×1
Astrodon OIII 5nm: 4×1800 “bin 1×1
Astrodon SII 5nm: 2×1800 “-20C bin 1×1
Accumulation: 5.0 hours
Avg. Age of the Moon: 0.49 days
Avg. Phase of the Moon: 0.27%
Location: Home Observatory, Home, Worcestershire, United Kingdom

Author: Paddy

Astrophotography of the day by SPONLI 04.12.2014