
Target Details
The Cigar Galaxy (Messier 82) is a starburst galaxy about 12 million light-years away in the constellation Ursa Major. With a diameter of 37,000 light-years it is much smaller than the Milky Way, yet it is about five times more luminous than the whole Milky Way and has a center one hundred times more luminous than our galaxy's center.
M82 was previously believed to be an irregular galaxy. In 2005, however, two symmetric spiral arms were discovered in near-infrared (NIR) images of M82. The arms were detected by subtracting an axisymmetric exponential disk from the NIR images. Even though the arms were detected in NIR images, they are bluer than the disk.
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.