NGC688
The Crescent Nebula (NGC 6888 or Caldwell 27) is an emission nebula in the Cygnus constellation, about 5000 light years away. 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 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.
Photo Details
Telescope: Sky90@4.5 405mm
Camera: Asi1600MMC-pro, Filter wheel, ZWO 36mm LRGBHSO filters
Mount: NJP Takahashi
Guiding: Off-axis
Exposure: H 36x5min OIII 36x5min
When: April 2018
Other information: My first bi-color
Photo Details
Telescope: Celestron C8N (1000mm)
Camera: Sbig ST-2000XM, Filter wheel, Baader 1.25" LRGB filtes
Mount: NJP Takahashi
Guiding: Self-guided
Exposure: HRGB 7h
When: ---
Other information: my first HA with this newton