I guess I’m not quite done with galaxy season yet. Hearing of yet another new supernova observation in NGC 6946, aptly nicknamed the Fireworks Galaxy, I couldn’t resist spending some time on it. I’ve also been working to fix problems in my home-built motorized focuser (first, with the world’s worst soldering job I had shorted some of the leads from the controller to the motor, then I messed up the setscrews in the flexible shaft coupling between the motor and the focuser) and wanted to test my repairs (they appear to have been successful in that automated focusing works again without much backlash). It took a couple of nights with some cloud dodging to get both the luminance and color data. I was happy to see that the supernova, SN 2017aew, is still bright. This galaxy lies behind a rich foreground star field that I find very pretty. I deliberately framed the shot to include what appears to be a nice open cluster in the bottom right of the image. SN 2017aew is marked in the B version.

Date: 24-25 May 2017

Subject: NGC 6946 (Fireworks Galaxy) and its latest supernova, SN 2017aew

Scope: AT8IN + High Point Scientific coma corrector

Filters: ZWO 31 mm diameter unmounted L, R, G, B

Mount: EQ-6 (EQMOD 2.000j)+PEC

Guiding: Orion Thin Off-axis Guider + DSI +PHD 2.6.3.2 (Win 10 ASCOM) using predictive PEC algorithm

Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21

Acquisition: Sequence Generator Pro 2.6.0.23

Exposure: 20x120 R, 18x120 G, 20x120 B, 36x600 L

Stacking: Neb 4.1.5, flats & darks, trans+rot align, Nebulosity 1.5σ stack and align.

Processing: StarTools 1.4.327: Stretched and deconvoluted the luminance. Combined RGB in Neb 4 and stretched, color balanced, and sharpened in StarTools. Layered luminance over RGB in Photoshop CC 2014 and used curves to decrease the luminance a bit. Boosted the vibrance a lot and saturation a little. Carboni’s Astronomy Tools star size reduction. AstroFrame.