105 hours on M81, M82 and the elusive IFN

This is my longest project so far in 20 years of astrophotography, totaling 105 hours over a 3 months of imaging.  I knew from the onset that this amount of total acquisition time had to be invested if I want to record that very faint signal of IFN (Integrated Flux Nebula) that I was after.

Galaxies Messier 81 and Messier 82 can be seen along with the faint tendrils of the IFN in Ursa Major. The bright glow from one of Ursa Major's brightest stars, the variable star 27 Ursae Majoris, can be seen as a smudge off to the mid-upper left.  M81 and M82 are located about 12 million light years away. The IFN is much closer and associated with our own galaxy, the Milky Way.

The IFN is comprised of extremely faint gas and dust that is illuminated by the combined flux of light of stars in the Milky Way. These clouds are located several hundred light years above the plane of the Milky Way. Some of the nebulosity is visible with a faint blue color from scattered and reflected starlight, while other portions emit red light from faint luminescence.

To give an idea of how faint the IFN is, 36 hours worth of total exposure with just luminance data (L channel in mono) was specially processed to bring out the faint nebulosity while attempting to retain detail in the bright galaxies.

(IFN using Chroma Luminance filter at 36 hours)

M81, right center, is a grand design spiral galaxy that forms a physical pair with irregular starburst galaxy M82 at left center. Several other galaxies are also visible in the field including Holmberg IX, a faint irregular dwarf satellite of M81 visible just below it. NGC 3077 is below and a little to the right of M81, and NGC 2976 is above and to the right. NGC 2985 is near the left-center edge of the image as well as NGC 3027 just below it. UGC 5139 is the blue galaxy to the left of the brightest part of the IFN.

OTA: William Optics Redcat 71 WIFD
Mount: ZWO AM5
Camera: ZWO ASI6200MM Pro (full frame)
Gain: 100
Cooling Temperature: -10 degrees celsius

Filters:
Chroma Luminance⚪ 426 x 300s = 36 hrs
Chroma Red🔴 154 x 300s = 13 hrs
Chroma Green🟢 155 x 300s = 13 hrs
Chroma Blue🔵 155 x 300s = 13 hrs
Chroma 3nm Ha 🟣179 x 600s = 30 hrs
105 hours total acquisition time

Auto-guiding: ZWO ASI174MM Mini and ZWO OAG-L
Auto-focusing: ZWO EAF
Control: ZWO ASIAIR Plus

Calibrated and Processed in Pixinsight.  Thanks to Jeff Horne for some integration and layering magic!

Imaged from Flagstaff, Arizona in class 2 Bortle skies.
https://NAZObservatory.com