November 21, 2024

M81 – Spiral Galaxy in Ursa Major

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” Baader Fringe Killer (minus V)

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

Exposure: 47x60sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 64x1/125s sky flats taken at dusk

Average Light Pollution: Bortle 8, fair transparency

Lensed Sky Quality Meter: 18.6 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

This is the last image in this image set taken with the Unitron 510.

M81 is a beautiful spiral galaxy that is interacting with the nearby M82. The sky conditions for imaging this delicate galaxy were far from optimal, but it is still neat to see the beautiful sweeping arms sprinkled with star forming regions resulting from a close encounter with M82. Very pretty.

M81 is low in the northeast during the early evening and is high overhead after midnight.