Sharpless 108 (Gamma Cygni Nebula)

The Gamma Cygni Nebula, also known as the Sadr Region or IC 1318 or Sharpless 108, is a diffuse emission nebula that can be seen around Sadr (Gamma Cygni), the star at the center of the Northern Cross, which marks the heart of Cygnus, the Swan. Despite the name, the star and the nebula are unrelated. Even though it looks embedded in the nebulosity, Sadr is approximately 1,800 light years distant, while the nebula is much further away, at 4,900 light years.

The Gamma Cygni Nebula is considered an emission nebula because it is ionized by the radiation of the nearby stars and it emits visible light as a result. The visible portion of the H II region stretches over an area more than 100 light years across. The nebula is illuminated by an O9-class star which is visually obscured by interstellar material.

Imaging Telescope: Vixen ED81s f/7.7 

Mount: Skywatcher HEQ5 Synscan Pro (belt mod) 

Camera: QHY 533M 

Filter Wheel: QHY CFW3S-SR 

Filters: L,R,G,B

Guiding camera: ZWO ASI120MM Mini (mono)

Guidescope: SkyWatcher EvoGuide 50ED

Constellation: Cygnus

Date: 12-13 August-2023 

Location: Sekoulas - Ileia - Greece - Albireo Observatory 2

Sky brightness: B2

Exposure Time: 

L: 12x600 sec (gain: 56.00, offset: 12.00) 0°C bin 1×1 

R: 12x600 sec (gain: 56.00, offset: 12.00) 0°C bin 1×1 

G: 12x600 sec (gain: 56.00, offset: 12.00) 0°C bin 1×1  

B: 12x600 sec (gain: 56.00, offset: 12.00) 0°C bin 1×1

Ha: 4x1800 sec (gain: 56.00, offset: 12.00) 0°C bin 1×1

Calibration Frames: Darks, Flats, Dark Flats 

Acquisition: ACP Expert, MaximDL 

Processing: Pixinsight, Photoshop