Sadr region crescent nebula

The Sadr Region (also known as IC 1318 or the Gamma Cygni Nebula) is the diffuse emission nebula surrounding Sadr (γ Cygni) at the center of Cygnus's cross. The Sadr Region is one of the surrounding nebulous regions; others include the Butterfly Nebula and the Crescent Nebula. It contains many dark nebulae in addition to the emission diffuse nebulae.

 

Sadr itself has approximately a magnitude of 2.2. The nebulous regions around the region are also fairly bright.

 

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.

 

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".

 

EQ6R Pro mount

William Optics GT81 iv Scope

Asi2600mc camera cooled to -10c

Optolong L Extreme Filter

ASIAIR Pro

ZWO EAF

ZWO mini guide scope and camera

 

50 x 300 second exposures

30 x darks

30 x dark flats

30 x flats

 

Stacked and processed in Pixinsight

 

Bortle 6 Sky (Kent UK)

Done