10,600 ± 1000 ly

Here’s another globular I’ve somehow missed until now. M22 is just above the galaxy’s central bulge, so this part of the sky is full of stars. I took this data and then got caught up in other things without finishing the processing, but I also have frames taken as it was rising over the mountain side and not being able to match the stars to other globulars I have imaged recently I finally did an astrometry.net plate solve and realized my rising target was M22 and that I have lots of other data to work with. So I processed these subs and will try to figure out how to make a movie of the cluster coming up over the snowy mountain side as well.

Date: 24, 26 May 2020
Subject: M22
Scope: AT8IN+High Point Scientific Coma Corrector
Filters: ZWO 31 mm diameter unmounted R, G, B
Mount: EQ-6 (EQMOD 2.000j)+PEC
Guiding: Orion Thin Off-axis Guider + ASI120MM-mini +PHD 2.6.8 (Win 10 ASCOM)
Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21
Acquisition: Sequence Generator Pro 3.1.0.479
Exposure: 45x180 R, 34x180 G, 50x180 B
Stacking: Deep Sky Stacker 4.2.3 (64-bit) dark+flat+bias, κ-σ stacking with κ = 1.5
Processing: StarTools 1.6.394RC: Composed R, G, & B accounting for total integration times in creating a combined synthetic luminance. Cropped, developed (87%), HDR (reveal all), deconvoluted slightly (2 pixels), and untrack denoised. In Photoshop, slight levels adjustment to darken the background. AstroFrame.