Capturing the Cygnus Wall in Glorious SHO Hubble Palette

Welcome back to the blog, fellow stargazers! Today, we're diving deep into the cosmos to explore a truly spectacular rendition of the Cygnus Wall, a prominent feature within the vast North America Nebula. This image, rendered in the iconic SHO (Sulphur, Hydrogen, Oxygen) Hubble palette, showcases the intricate details and vibrant gases that make our universe so awe-inspiring.

A Symphony of Gas and Light

The Cygnus Wall, stretching over 20 lightyears, is a testament to the immense power of stellar formation and radiation. While once thought to be illuminated by the star Deneb, further research revealed a hidden star, dubbed the Bajamar Star, located behind the dark nebula, is the true source of the energetic UV radiation that excites the gases in this region.

This particular capture was achieved over 5 hours of integration time, spread across two nights, under conditions of 100% lunar phase and sub-average seeing. Despite these challenges, the resulting image is nothing short of phenomenal.

The Technical Details: A Glimpse Behind the Curtain

This image is a product of meticulous planning, specialized equipment, and a sophisticated processing workflow. The astrophotographer, using a Skywatcher 130PDS Newtonian telescope, captured data with a QHY minicam8 (mono version), marking their first light with this camera. This move from an OSC (One-Shot Color) camera to a mono setup, despite a smaller sensor, has proven to be a rewarding switch.

Acquisition Details:

• Integration Time: 5 hours over 2 nights
• Filter Palette: Hubble SHO
  • Sulphur (S): 20 x 300s
  • Hydrogen (H): 20 x 300s
  • Oxygen (O): 20 x 300s
• Calibration Frames: 35 darks, 35 bias, 3 x 35 flats
• Conditions: 100% lunar phase, sub-average seeing, no wind or dew.

Equipment Used:

• OTA: Skywatcher 130PDS Newtonian
• Camera & Filter Wheel: QHY minicam8
• Guiding: WO uniguide 50 + asi224mc + UV/IR cut filter
• Mount: Rowan belt modded HEQ5
• Control: Morefine M9 mini PC, Pegasus astro powerbox micro
• Capture Software: NINA

Processing Workflow (PixInsight & Affinity Photo 2):

The journey from raw data to the final image involved a comprehensive suite of tools in PixInsight, including:

• WBPP (Weighted Batch PreProcessing): For initial stacking of S, H, and O channels.
• BlurXterminator & NoiseXterminator: For advanced deblurring and noise reduction.
• Seti Astro Statistical stretch: For a robust stretch of the data.
• StarXterminator: To isolate and manage stars.
• GHS (Generalised Hyperbola Stretch): For further tonal adjustments.
• LHE (Local Histogram Equalization): To enhance local contrast.
• Linear fit: Aligning the O and S channels with H as the reference.
• RGB Combination & SCNR: Creating the SHO color combination with a 30% SCNR (green removal).
• Foraxx script: Applied selectively to stars.

The processed SHO image, along with individual H and H+LHE channels, and Foraxx stars, were then exported to Affinity Photo 2 for final touch-ups:

• Layering of SHO image, color noise reduction, selective color adjustments.
• H channel as Luminosity at 50%.
• H+LHE channel as Soft Light at 72%.
• Vibrance, Curves, and Clarity adjustments.
• Addition of Foraxx stars using Screen blend mode.

A Rewarding Endeavor

The astrophotographer notes that this is their first experience with the QHY minicam8 mono camera and expresses great satisfaction with the results, even with the minor inconvenience of needing an external powered USB hub due to the camera's lack of an integrated one. This image, captured in a Bortle 5 sky, is a testament to the dedication and skill involved in modern astrophotography.

What do you think of this stunning capture? Share your thoughts in the comments below!