Abell 80 in Lacerta
Abell 80 (PK 102-05.1, PN G102.8-05.0) was cataloged by George Abell in 1966. It appears to be a bipolar planetary viewed nearly face-on. This PN is 162 x 120 arcsecs and about magnitude 15.2, and is located 5700 light years away. This image is Ha for luminance and Ha/OIII for nebula color, overlayed on an RGB star field.
Exposure: Total exposure time about 18.5 hours. 27:25 x 20 minutes Ha:OIII, 19:19:25 x 2 minutes RGB. All bin 1x1. Captured September to November 2019.
Light pollution: SQM ~18.2 (Red/white zone border, Bortle 7-8, NELM at zenith about 4.5)
Image scale at capture: 0.6 arcsecs/pixel = f/5.7
Scale of presentation: 0.84 arcsecs/pixel (75% size)
Equipment:
Scope: C11 (standard, not Edge) with Celestron 0.63 reducer imaging at f5.7
Mount: Paramount MX+, connected via ASCOM Telescope Driver 6.1 for TheSkyX, with MKS 5000 driver 6.0.0.0
Camera: SXVR-H694, connected via SX ASCOM driver 6.2.1.17140 (SX 1.2.2 also installed)
Filter wheel: Atik EFW2 with 7x1.25 carousel and Artemis 2.4.3.0 driver
Filters: Astrodon Type IIi LRGB
Rotator: Optec Pyxis 2", connected via Andy Galasso's 0.4 driver (Optec Pyxis Rotator AG)
Focuser: Rigel Systems GCUSB nStep with driver version 6.0.7
OAG: Orion Thin OAG
Guide cam: Lodestar (first generation). 4 second exposures
Automation SW: Sequence Generator Pro 3.0.3.169
Guide SW: PHD2.6.3, connected to guide cam via native SXV driver
ASCOM: ASCOM 6.3.0.2831
Platesolving: PlateSolve 2, failover to local Astrometry.net 0.19 server
Collimation: Metaguide 3, using ASI120MM connected via ZWO Direct Show driver 3.0.0.2
Processing Workflow by Workspace in PixInsight 1.88
1. Calibration
Weighted BatchPreProcessing with flats, darks, and bias, using Cosmetic Correction and weighting by SNR and FWHM.
2. Stack and Mure Denoise
Blink to preview frames and remove some bad images
Image Integration
Mure Noise Reduction on each channel
Channel Combination to merge RGB channels
Dynamic Crop
3. Narrowband Linear Processing
Dynamic Background Extraction
Deconvolution on Ha image, using Dynamic PSF and a mask to protect the star field.
4. Narrowband Stretching
Histogram Trans x 2
Curves Trans
Noise Reduction with TGV Denoise and Multiscale Median Transform (following David Ault’s Astro Imaging Channel tutorial.)
Mild Local Histogram Equalization on Ha channel
5. RGB Linear Processing
Dynamic Background Extraction
Photometric Color Calibration
6. RGB Stretching
Histo Trans x 2
Create star mask with Advanced Star Mask script
Boost saturation of stars slightly with Curves
7. Merge Narrowband and RGB Stars
Merged narrowband channels in PixelMath, mapping Ha:OIII:(85% OIII+15% Ha) to R:G:B
Color Mask script on cyan, then Curves to shift cyan/teal to blue
LRGB Combination using Ha for luminance and merged narrowband for color
In Photoshop, layer nebula onto RGB stars image with a mask.
Create color layer and use Radial Blur to reduce comatic blue halos on stars near edges of FOV
8. Final
Resample to 75% scale
ICC Profile to sRGB
Save as 100% quality JPG
