The Fireworks Galaxy NGC 6946: This is the result from three nights. It’s amazing to see how fast you can swamp the readnoise with the ASI533MC. The sensitivity seems to be roughly 4x that of my old Nikon D3400. And this is with the uncooled model! Sadly, my seeing is mostly meh. It’s always 3“ at my place. Rarely it’s 2.5“ and similar rarely it’s 3.5“. Kind of boring.

This image was done with a Celestron C8, the original 0.63x reducer/corrector and an ASI533MC (uncooled). Everything was mounted on a Skywatcher HEQ5 (with Rowan Belt Mod) together with 15 kg of counterweights on my backyard pier. During processing I had to toss 40% of my frames from twining the nights due to wind and clouds. The HEQ5 is small for a C8 after all and it wasn’t the best weather. Integration time is a bit over 14 hrs from a three nights.

Raw stack from PixInsight can be downloaded here. It was calibrated with bias and flat frames. Standard settings from WBPP (2024) were used, incl. CFA drizzle at scale 1. It is slightly oversampled. This is 284x 180s at gain 101.

My processed imaged with details can be found on Astrobin. You can read about the this galaxy here on Wikipedia.