Lobster Claw and Bubble Nebula Complex

Captured in a single frame we find a lobster claw, a bubble carved out by a giant star, various smaller nebula, multiple star clusters, and molecular dust lanes that shape a particularly busy area of the night sky.  Prominently displayed in the upper right is the Lobster Claw Nebula (SH2-157), with its blue green oxygen emission lanes adjacent to the richly detailed hydrogen alpha emission regions.  The Bubble Nebula (NGC 7635) in the bottom center is approximately seven light years in diameter and is formed by a star 45 times more massive than the Sun, as it pushes out the surrounding molecular cloud. NGC 7635: The Bubble Nebula | Science Mission Directorate (nasa.gov).  The Northern Lagoon Nebula (NGC 7538), shining brightly in the upper left, is an active area of star formation and is home to one of the biggest discovered protostars, at about 300 times the size of our solar system and growing. NGC 7538 - Wikipedia.  The M52 open star cluster, in the lower left, is approximately 5,000 light years from Earth, but the Door Mouse (NGC 7510) cluster in the upper center right is farther away at 11,400 light years.  Also take note of the various ink black clouds, one to the right of the Lobster Claw, another between the claw and Bubble Nebula, and a scattering of dark clouds in the upper left. These clouds appear to block out light from the underlying hydrogen and oxygen emission layers.

Mouse over for a cropped Bubble Nebula.  Starless versions are available as separate revisions.

I decided to push the limits with this scope and go long on a single target.  At 58 hours of total time on target, more time was spent shooting this project than all my previous projects combined. I kept just under 49 hours of the best subframes with the remaining 9 going straight to trash. The longer integration time allowed me to pull out a lot of detail. I used GHS for the first time on a finished project to keep from blowing out the Bubble Nebula and Northern Lagoon.  RGB stars were captured separately and lightly stretched.  The results are surprising for a 71mm aperture scope shot from a Bortle 7. 

Processing performed in PixInsight using the following steps:

1. WBPP
2. RGB Stars
1. LRGB Combine
2. DBE
3. BlurXTerminator Correct First
4. Bill Blanshan PixelMath Linked Stretch
5. NoiseXTerminator
6. StarXTerminator
7. Curves
8. Bill Blanshan ModifiedSCNR


3. SHO
1. DBE per channel
2. BlurXTerminator Correct First
3. StarXTerminator
4. GeneralizedHyberbolicStretch
5. NoiseXTerminator
6. PixelMath SHO Foraxx
7. Bill Blanshan ModifiedSCNR
8. NoiseXTerminator
9. Ha Luminance
1. LocalHistogramEqualization
2. MultiscaleLinearTransform
3. HDRMultiScaleTransform


10. LRGBCombination
11. Curves
12. NoiseXTerminator


4. Re-screened stars
5. Bill Blanshan PixelMath StarReductionMethod3
6. DynamicCrop