M101 – Face-on Spiral Galaxy in Ursa Major

Telescope: Meade SN10 at f/4, Orion Atlas EQ-G

Camera: Full Spectrum Modified Nikon D810

Filter: GSO IR Blocking Filter

Guide scope: Williams Optics 50mm, ASI290MM mini, PHD

Exposure: 94x30sec, ISO 200, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/50sec, tee shirt flats taken at dusk

Average Light Pollution: Red zone, poor transparency

Lensed Sky Quality Meter: 18.4 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

M101 is located high overhead at dusk.