Contains:  NGC 7337, NGC 7335, NGC 7331, NGC 7320, NGC 7319, NGC 7318, Stephan's Quintet, NGC 7317
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Deerlick Group and Stephan's Quintet

Technical card

Resolution: 3478x2306

Dates:Sept. 9, 2017Sept. 24, 2017Sept. 25, 2017Sept. 30, 2017Oct. 1, 2017

ZWO Blue: 78x150" (gain: 150.00)
ZWO Green: 86x150" (gain: 150.00)
ZWO H-alpha 7nm: 37x300" (gain: 150.00)
Baader IR-Cut Moon & Skyglow Neodymium: 72x150" (gain: 150.00)
ZWO Red: 83x150" (gain: 150.00)

Integration: 16.4 hours

Avg. Moon age: 9.45 days

Avg. Moon phase: 56.96%

Bortle Dark-Sky Scale: 8.00 job: 1755385

RA center: 339.133 degrees

DEC center: 34.261 degrees

Pixel scale: 0.914 arcsec/pixel

Orientation: 263.439 degrees

Field radius: 0.530 degrees

Data source: Backyard


I think I let this one get the better of me and I almost gave up halfway through it. This image was also affected by collimation problems I initially couldn't figure out. Both a spider screw and a focuser screw came loose due to the seasonal temperature changes. If it were one or the other, I think I would have solved it faster, but I spent about 4 clear nights wondering why I was collimated around Polaris, but completely off at the zenith. I ultimately finished only because I had a number of clear nights in a row (from 9/24 on, minus 2 nights) and didn't have a subject picked out that was up as soon as it got dark. I'm glad I finished it, but this one didn't come out as well as I was hoping. It's better than last year's attempt, but I think I need a higher focal length scope to really make this one work the way I want. I'm hoping to get an 8" RC and Astrophysics 0.67x reducer some time next year. I think it'd frame this one nicely.

I simplified the acquisition details a bit, because I spent too many nights capturing different datasets. I had to trash a lot, but data that made it into this was captured on 9/09, 9/11, 9/13, 9/24, 9/25, 9/26, 9/28, 9/29, 10/01 and 10/02.

I have never had so many subs affected by planes - I should upload a stack of just 'plane' subs - I probably have at least 25.



Chris Sullivan
License: None (All rights reserved)

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Deerlick Group and Stephan's Quintet, 


            Chris Sullivan