November 16, 2024

M81 – Spiral Galaxy in Ursa Major

M81 – Spiral Galaxy in Ursa Major

Telescope: Meade 12” LX850 ACF @ f/8, Orion Atlas EQ-G

Camera: ZWO ASI071 MC Pro, -10C, Gain 200

Filter: Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, ASI290MM Mini, PHD2

Exposure: 21x240sec, saved as FITS

Darks: 32x240s, saved as FITS

Flats: 32x1sec, Tee shirt flats taken at dawn

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

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

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

I was a bit surprised at how well this turned out. The sky conditions were very poor with a fair amount of haze and very poor seeing. The result was a soft image with very low contrast. Processing recovered more detail than I thought it would and down-sampling the image helped to sharpen it a bit. Not a bad result, though I’m looking forward to trying this again under better conditions. So much to try, so few clear nights…

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 tinged with blue star forming regions resulting from a close encounter with M82.