Monthly Archives: June 2020

M13 – Hercules Cluster

I have a guilty pleasure: I like globular clusters. I should put more effort into more challenging classes of objects – diffuse nebulae and galaxies, but I’ve always loved GCs, even though they are easy to see. M13 is my favourite.

This was a test image last night, after a couple of days of maintenance, collimating the scope and then re-doing the mount polar alignment and pointing model.

Exposure Luminance: 60 minutes (20 x 3 minutes)
Colour: 15 minutes (5 x 1) of each of Red, Green, Blue
Camera QSI583wsg, with Astrodon LRGB filters, running at -15°C
Image scale 0.69 arceconds/pixel (luminance), 1.38 (colour)
Telescope AT8RC
Mount Paramount MX+
Guiding Autoguided with Starlight XPress Lodestar
Processing 32 dark frames per sequence
32 flat frames per filter
Sigma-clip mean combination on the darks and flats
Sum-combination on the light frames
Aligned, combined, and deconvolved with CCDStack2