Pinwheel galaxy M101 23/03/2017

Date 23-24/03/2017. The Pinwheel galaxy (M101) was my second target of the night. It is a favourite of mine, being ever present and normally high in the sky. The gradient effect seen in my image of the Leo triplet is not present here because of the high altitude of M101. I spent the most time on M101 to try and coax as much detail from the edges of M101 and the other small galaxies in the image. Although faint, these smaller galaxies are viable, NGC 5477 is a small patch to the left (RA-) of M101, NGC 5473 is a dense patch in the top left of the image and NGC 5455 is a star like point of light just below (DEC-) M101.

Weather: The sky was clear with good transparency and seeing. Wind was strong however and I lost quite a few frames because of vibrations. Temperature was about 3-5 degrees.

Optics and camera: Skywatcher Evostar 120 F/D=8.33 (Achromat) with a Baader UHCs filter (for removing light pollution). The camera was a IR-filter removed Canon 600D.

Settings: 64 x 3 minute lights, 50 darks from library, 50 flats taken recently and 50 bias frames. ISO 800.

Mount: Skywatcher AZ-EQ6 with extension pillar.

Processing: The Lights and calibrations frames were processed using Deep Sky Stacker. I set the star detection thresholds to values that caught about 30-40 stars. The final images were stretched in RGB and I then balanced the histograms to retain white balance. Luminance was tweaked to show faint detail.