Capturing Our Galactic Neighbor: M31 Under Bortle 6 Skies
After five months immersed in the hobby of astrophotography, I finally had the opportunity to capture our closest galactic neighbor, the magnificent Andromeda galaxy (M31). This endeavor required a significant journey – relocating my entire imaging rig across the country during my summer vacation. The goal was to escape the light-polluted, sub-18 SQM hellscape of my home for the clearer, darker skies of southern France, where I found myself under Bortle 6 conditions. The difference, as you can imagine, was truly night and day!
This image is the first part of a planned 'summer twins' project, which also includes imaging the Triangulum galaxy (M33). You can expect to see M33 featured soon!
Acquisition Equipment and Details:
- Mount: Skywatcher Star Adventurer GTI equatorial mount
- Telescope: Askar SQA55 f/4.8
- Camera: ASI2600MC (Gain 100, Offset 50, Cooled to -10°C)
- Sub-exposures: 474 x 60s subs
- Total Integration Time: 7 hours 54 minutes
- Sky Conditions: Bortle 6
Processing Workflow:
My post-processing involved a robust suite of tools, primarily PixInsight, with final touches in Lightroom:
- Stacking: WeightedBatchPreprocessing (WBPP) with Drizzle x1, Drop Shrink 0.9, and the square function.
- Gradient Removal: Gradient Correction and GraXpert background extraction.
- Color Calibration: SPCC.
- Deconvolution/Sharpness: BlurXterminator.
- Stretching: Statistical stretch.
- Star Reduction: StarXterminator.
- Color Balance: SCNR on a star mask.
- Color Enhancement: Curve Transformations (Saturation and RGB).
- Noise Reduction: NoiseXterminator.
- Final Touches: Lightroom adjustments.
This image represents a significant milestone in my astrophotography journey, and I'm thrilled with the results achieved under these much-improved skies. The depth and detail are a testament to both the equipment and the dedication to capturing these celestial wonders.
