M101 – Face-on Spiral Galaxy in Ursa Major

Telescope: Meade SN6 Comet Tracker at f/3.6, Orion Atlas EQ-G

Camera: Full Spectrum Modified Nikon D5300, Baader Mk III MPCC

Filter: Orion Imaging Skyglow Filter

Guide scope: Orion 50mm, ZWO ASI120MM mini

Exposure: 142x60sec, ISO 200, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

Average Light Pollution: Red zone, Bortle 8, poor transparency, bright moonlight

Lensed Sky Quality Meter: 18.1 mag/arc-sec^2

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Backyard Nikon, Deep Sky Stacker, Nebulosity, Photoshop

M101 is a wonderful face-on spiral just north of the handle of the Big Dipper. It is also something of a monster, nearly twice the size of the Milky Way, making it one of the largest spirals known. This field also shows several other galaxies, some of which are satellites of M101. At the bottom of the field in NGC 5474, a dwarf spiral

M101 is a circumpolar object that never sets from mid-northern latitudes. It rises with the handle of the Big Dipper and is visible in the northeast in the late evening and is high overhead at dawn.