Type: Grand Design Spiral

Constellation: Ursa Major

Distance from Earth: 12 million light-years

About: Johann Elert Bode initially detected the galaxy on December 31, 1774, earning it the nickname “Bode’s Galaxy.” Then, in 1779, Pierre Méchain and Charles Messier independently confirmed Bode’s discovery, leading to its inclusion in the Messier Catalog.

Imaging Project Information: This image is the combination of 2 years of imaging data. I have photographed and processed M81 several times with different telescope imaging systems, but this is the first combining multiple years of data. Thanks to some tips received from viewers during an episode of AstroWorld TV,  I learned I could integrate past calibrated data with new data into Pixinsight. Using Weighted batch Preprocessing (WBPP) would not only register and calibrate the new data but also realign and integrate into the old building a data set that can be processed into a new image. 

I plan to add to this data set in the future, mostly adding to the Luminance (data in this channel is what gives images more overall detail), and the Hydrogen-Alpha channel adds more detail to the reddish-pink H II regions and hydrogen-rich nebulae that may be within the galaxy’s arms.  

Imaging Telescope: Celestron EdgeHD 8″ Schmidt-Cassegrain

Imaging Camera: ZWO ASI533MM Pro

Mount: iOptron CEM60 

Guiding: Celestron Off-Axis Guider and ZWO ASI174MM Mini guide camera

Filters and Frames:  Antlia Pro V LRGB and Edge Pro 4.5nm Hydrogen Alpha

H-Alpha – (12x300s) (Gain 100), and  (12 x 300s) Gain 0
Lum – 18 x 300s @ Gain 100
Red – 86 x 60s @ Gain 0
Green – 86 x 60s @ Gain 0
Blue – 86 x 60s @ Gain 0

Accessories: ZWO ASiAir Plus, MeLe Overclock 4C mini PC (Image Acquisition and Sequence Management), ZWO EAF Electronic Focuser, Primalucelab Essato 2″ LP Microfocuser (Telescope Focusing), ZWO EFW 8 x 1.25″ Filter Wheel, Pegasus Astro Powerbox Advanced (Power Distribution), Pegasus Astro USB Hub (Device Data Distribution), Pegasus Astro Uranus Meteo Sensor (Weather Tracker)

Software: Acquisition – N.I.N.A., Autoguiding: PHD2,  Image Preprocessing: Pleiades Astro Pixinsight and Aries Astropixel Processor, Image Postprocessing: Pleiades Astro Pixinsight, Adobe Lightroom Classic

Acquisition Period: 5/20, 5/21, 5/24 (2023), 3/20-21 (2024)