Reply to comment

NGC 6888

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 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[citation needed] 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.

It is a rather faint object located about 2 degrees SW of Sadr. For most telescopes it requires a UHC or OIII filter to see. Under favorable circumstances a telescope as small as 8 cm (with filter) can see its nebulosity. Larger telescopes (20 cm or more) reveal the crescent or a Euro sign shape which makes some to call it the "Euro sign nebula".

L = 18 * 1200 sec. bin1, RGB = 9 * 900 sec. bin2, HaOIII = 10 * 1200 sec. bin2, n the each filters.

Total exposition - 19.5 hours

Pixinsight 1.8, Lightroom.

NGC 6888

Reply

The content of this field is kept private and will not be shown publicly.
  _  _     _  _   
| || | | || |
| || |_ | || |_
|__ _| |__ _|
|_| |_|
Enter the code depicted in ASCII art style.