You may recall the recent mega-collaboration on M106 by multiple imagers, with over 250 hours of integration time behind it.  One of those collaborators, Andrew, who is my “co-author” for this image, suggested we should do a local, northeastern U.S. collaboration between us as a follow-up.  It turns out we already had the data on hand for a ~17 hour project on M33, resulting in a “retro-collaboration” from 2021 data.  What could be better than getting a new image without collecting any data? 

Andrew recorded his LRGB data at the Bortle 2 dark site last fall with his TS-Optics Photoline 130 mm f/7 FPL53 Triplet while I was imaging something else with my Esprit 100ED at f/5.5 about 30 feet away.  I then decided to image M33 from home in my Bortle 4/5 backyard, but we never thought to combine our data for some reason.  Both of us recorded H-alpha from home.  After a little brainstorming, Andrew was able to combine the data using Astro Pixel Processor to obtain composite L,R,G,B, and H channels from both telescopes.  We applied 2x drizzle after the fact in order to make deconvolution a bit more productive.

Andrew used a ZWO ASI 2600MM Pro camera with 2” ZWO LRGB filters, and I used a QHY268M camera with 36 mm Baader LRGBH filters.  For more specifics on the gear and software used by Andrew, please visit his version of the image here:

Link to Andrew's Version

I processed the data using Deep Sky Stacker, GIMP, and MLUnsold ImagesPlus, whereas Andrew mostly used PixInsight after he was done combining the data in APP.  I spent way too much time obsessing over star size reduction, but I am really pleased with the results.  It’s fun to see two different results from the same data set, with all kinds of gear involved.


Total integration time: 16 h 53 min


Andrew's meta-data:

TS-Optics Photoline 130 mm f/7 FPL53 Triplet

All LRGB subs are 180”, gain 0, -5C, shot at Bortle 2 site

L is bin1x1, RGB bin 2x2L - 11x180” (33’)

R - 30x180”(1.5hrs)
G - 32x180”(1hr 36’)
B - 21x180”(1hr 3’)

Ha is 300” subs at gain 100, -5C, and bin1x1

Ha - 21x300”(1hr 45’)Total integration - 6hrs 27’

My meta-data:

Telescope: Esprit 100ED at f/5.5 with stock field flatterner
Mount: Software Bisque Paramount MX
Camera: QHYCCD QHY268M
Filter wheel: Atik EWF2
Filters: Baader LRGBH 36 mm

Dates:
    Sept. 7, 2021 ·  Sept. 8, 2021 ·  Sept. 30, 2021 ·  Oct. 1, 2021

Frames:
    Baader Planetarium 36mm H-Alpha: 22x300" (1h 50') (gain: 56.00) -10°C bin 1x1
    Baader Planetarium LRGB 36mm: 129x240" (8h 36') (gain: 56.00) -10°C bin 1x1

Integration:
    10h 26'

Avg. Moon age:
    12.47 days

Avg. Moon phase:
    16.59%

Bortle Dark-Sky Scale:
    4.00