markas
20-09-2017, 03:35 PM
GCs aren't the most entertaining subjects, but faced with high level haze, streaks of cirrus clouds and a lousy forecast for the rest of this dark period, I settled for M55, as I thought a GC was the best chance for a result in the conditions.
As luck would have it, the worst conditions were in force during half of the blue imaging, so a lot of Pixinsight cleaning up was necessary. After that, minimal processing: a little decon to sharpen the image a bit, Pixinsight's new Photometric Colour Calibration, and Histogram Stretch.
Although M55 has very low metallicity, it also has a relatively large number of 'blue stragglers' - thought to be the result of relatively recent star mergers and collisions.
ASA10N f/3.6; Moravian G3-16200; DDM85A; Astrodon filter set.
RGB only; 2.5min subs; total exposure 3 hours 20 min. FOV of this crop approx. 32' x 25'
As luck would have it, the worst conditions were in force during half of the blue imaging, so a lot of Pixinsight cleaning up was necessary. After that, minimal processing: a little decon to sharpen the image a bit, Pixinsight's new Photometric Colour Calibration, and Histogram Stretch.
Although M55 has very low metallicity, it also has a relatively large number of 'blue stragglers' - thought to be the result of relatively recent star mergers and collisions.
ASA10N f/3.6; Moravian G3-16200; DDM85A; Astrodon filter set.
RGB only; 2.5min subs; total exposure 3 hours 20 min. FOV of this crop approx. 32' x 25'