Clusters & Stars
Messier 103
Messier 103, a distant open star cluster in Cassiopeia 8,000–9,500 light-years away, photographed by Pete Lawrence.
Target details
Messier 103 (NGC 581) is an open star cluster in Cassiopeia and one of the most distant open clusters known, 8,000 to 9,500 light-years away and about 15 light-years across. It has around 40 member stars and is roughly 25 million years old. The eye is drawn to the bright star Struve 131, but that isn't actually part of the cluster – it just lies in the same direction.
Capture details
Data captured 17th October & 1st November, 2018.
14x 2 minute exposures with Blue filter (Binned 2x2).
15x 2 minute exposures with Green filter (Binned 2x2).
14x 2 minute exposures with Red filter (Binned 2x2).
25x 3 minute exposures with Luminance filter.
Total Exposure = 2.7 hours.
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
Automatic Background Extraction - To remove gradients. (Each Channel separately)
Linear Fit - To equalise the RGB channel brightness.
Channel Combination - To combine RGB channels.
Photometric Colour Calibration - To calibrate colours.
SCNR - To remove green cast.
Deconvolution - To tighten stars, 50 iterations. (Luminance & Red Only)
Multiscale Linear Transform - To noise reduce the Luminance only.
LRGB Combination - To blend my luminance image with my RGB image.
Histogram Transformation - To stretch the LRGB image.
Curves Transformation - To boost contrast.
Export as JPEG and import into Lightroom.
Increase Contrast (+20)
Darken Blacks (-20)
Increase Vibrance (+50)
Export final JPEG for upload.