The Cygnus Wall is the “Mexico” part of the larger North American Nebula (NGC7000). This area of the nebula is particularly bright and active, so makes a good subject for intermediate focal lengths when the full nebula cannot fit into the field of view.
The North American Nebula is situated in the constellation of Cygnus, close to the bright star Deneb. As it lies in the plane of the Milky Way, Cygnus is particularly rich in nebulous regions, though these can only be seen with long exposure photography. The nebula lies at a distance of 2,600 light years, is about 90 light years across and is one of the largest and brightest emission nebula in our night sky. The Cygnus Wall section shown above is an area of active star formation where the hydrogen gas is gradually collapsing to form new stars.
This image was taken using a cooled mono camera, using narrow-band filters that only pass the specific wavelengths of light emitted by Sulphur, Hydrogen and Oxygen molecules. Images taken with each filter are then stacked together to reduce noise, and assigned to the Red, Green and Blue colour channels to produce the colour image. This colour palette (known as SHO or Hubble Palette) was developed for the Hubble Space Telescope images as it is very effective in showing up fine details in the nebula. In “natural” colours, the nebula would be overwhelmingly red, and all the finer details would disappear. See my image of the North American Nebula taken with a standard DSLR to see this area in “natural” colour.
Image Details
- Date: 29th & 30th January 2024.
- Telescope: Altair Astro 72EDF. Focal Length: 432mm, Aperture: F6.
- Camera: Altair Astro 183MM Cooled Mono Astro Camera at Gain 200, Offset 40, Temp -10degC.
- Filters: H-alpha – Baader 7nm 2 inch filter. OIII – Baader 8.5nm 2 inch filter. SII – Antlia 3.5nm 2 inch filter.
- Mount: Skywatcher HEQ5.
- Guide Scope: Altair Astro 60mm.
- Guide Camera: QHY5LII.
- Exposure Details: H-Alpha: 11 x 500s (1hr 32min), OIII & SII: 13 x 500s (1hr 48min).
- Total Integration Time: 5hr 8min.