The Cigar Galaxy

Target details

The Cigar Galaxy (Messier 82) is a starburst galaxy in Ursa Major, about 12 million light-years away. At 37,000 light-years across it's much smaller than the Milky Way, yet it's about five times brighter overall, and its centre is a hundred times brighter than ours. It was long thought to be an irregular galaxy, until near-infrared images in 2005 revealed two symmetrical spiral arms.

Capture details

Data captured 6th, 7th & 26th January; 4th & 5th February, 2018.
14x 3 minute exposures with Blue filter (Binned 2x2).
15x 3 minute exposures with Green filter (Binned 2x2).
15x 3 minute exposures with Red filter (Binned 2x2).
147x 3 minute exposures with Luminance filter.
75x 10 minute exposures with Ha filter.

Equipment details

Skywatcher Quattro 200 CF
NEQ6 Pro
Atik 428EX Mono
Skywatcher ST-80
QHY5L-II

Processing details

This image was processed in Pixinsight & Lightroom.
Calibration and Stacking in Pixinsight using Batch PreProcessing
Dynamic Crop - To remove black edges & integration artifacts. (Each Channel)
Dynamic Background Extraction - To remove gradients. (R, G & B separately)
Automatic Background Extraction - To remove gradients. (Lum & Ha separately)
Deconvolution - To bring out some fine detail & tighten stars, 35 iterations. (Luminance & Ha separately)
Multiscale Linear Transform - Noise reduction. (Each Channel)
Histogram Transformation - To stretch the image.
Channel Combination - To combine RGB channels.
Photometric Colour Calibration - To calibrate colours.
SCNR - To remove green cast.
LRGB Combination - To blend my luminance image with my RGB image.
Channel Extraction - To split RGB.
Channel Combination - To merge Ha, G & B with Ha in Red channel.
HDR Multiscale Transform - To recover some detail in the galaxie's core.
UnsharpMask - To sharpen with mask in place to exclude stars & background.
Curves Transformation - To boost contrast.
Dark Structure Enhance - To boost detail in dark areas.
Curves Transformation - To further boost contrast.
Curves Transformation - Increase Saturation slightly in red channel with previous mask inverted to protect background & stars.
Curves Transformation - To decrease saturation of background, with lightness mask in place (stretched to clip black and boost mids).
TVGDenoise - To denoise background, with previous mask in place.

Export as JPEG and import into Lightroom.
Contrast Boost (+15)
Clip Blacks (-25)
Increase Saturation (+50)
Increase Red Saturation (+50)

Export final JPEG for upload.