Capturing the Andromeda Galaxy in HaRGB: A Deep Dive into Astrophotography

Behold, the majestic Andromeda Galaxy, M31, presented in a spectacular HaRGB composite! This project represents a significant milestone, the culmination of five nights of dedicated data collection and over 18 hours of painstaking exposure time. The result is a testament to the dedication and skill involved in deep-sky astrophotography.

This post showcases three distinct views of Andromeda: the primary HaRGB composite, an RGB-only rendition, and a Ha-only view. For those interested in the intricate details, starless versions of each image are also provided.

This project was not without its challenges, pushing my processing capabilities to new limits. However, the learning experience was invaluable, and I'm incredibly pleased with the final output, especially considering previous attempts. It's a truly satisfying achievement!

The Gear Behind the Shot

To bring M31 to life, the following equipment was utilized:

• Camera: ZWO ASI533MC Pro
• Telescope: William Optics ZenithStar 61 II APO with Field Flattener
• Filter: Optolong UV/IR Cut & L-eXtreme
• Guide Camera: ZWO 120mm mini
• Mount: Skywatcher Star Adventurer GTi

Acquisition Details

All data was collected under Bortle 5 skies, with the camera cooled to a stable -10°C.

• Lights (L-eXtreme): 122 x 300s (10 hours 10 minutes)

• Lights (UV/IR): 175 x 180s (8 hours 45 minutes)

• Total Integration Time: 18 hours 55 minutes

• Flats: 50

• Bias: 50

• Darks: 50

Processing Workflow

The journey from raw data to this final image involved a meticulous processing pipeline, primarily using Pixinsight:

• Ha & RGB Combination:
  • GraXpert for gradient removal
  • SPCC for color calibration
  • BlurXterminator for deblurring
  • NoiseXterminator for noise reduction
  • Initial GHS stretch
  • StarXterminator for star removal
  • Second GHS stretch
  • Curve level adjustment in Photoshop for each image
  • Combine Narrowband and RGB (for HaRGB composite)
  • HDR Multiscale Transform
  • Dark Structure Enhance
  • Curves adjustment
  • Star recombination
  • Final touches in Lightroom

It's moments like these that remind us of the vastness of the universe and the potential for life beyond our own planet. Andromeda, our closest galactic neighbor, is hurtling towards us, a spectacular dance in cosmic time.

For more of my astrophotography, feel free to check out my Instagram: