Hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  NGC 3917  ·  NGC 3931  ·  NGC 3953  ·  NGC3917  ·  NGC3931  ·  NGC3953  ·  PGC213886  ·  PGC213888  ·  PGC213892  ·  PGC213899  ·  PGC213900  ·  PGC2396278  ·  PGC2396289  ·  PGC2396788  ·  PGC2397526  ·  PGC2397658  ·  PGC2397890  ·  PGC2398035  ·  PGC2398810  ·  PGC2399182  ·  PGC2400472  ·  PGC2401133  ·  PGC2401727  ·  PGC2402241  ·  PGC2402633  ·  PGC2402958  ·  PGC2405438  ·  PGC2407686  ·  PGC2407838  ·  PGC2409656  ·  And 20 more.
Getting plate-solving status, please wait...
NGC 3953 & NGC 3917 - 8" RC, 



    
        

            Andrew Burwell
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NGC 3953 & NGC 3917 - 8" RC

Getting plate-solving status, please wait...
NGC 3953 & NGC 3917 - 8" RC, 



    
        

            Andrew Burwell
Powered byPixInsight

NGC 3953 & NGC 3917 - 8" RC

Imaging telescopes or lenses: GSO 8" f8 RC

Imaging cameras: ZWO ASI2600MC Pro

Mounts: 10Micron GM1000HPS

Focal reducers: Astro-Physics CCDT67

Software: Kstars/Ekos  ·  Astro Pixel Processor  ·  Adobe Photoship CC 2018  ·  PixInsight 1.8 Ripley

Accessory: MoonLite CSL 2.5" Focuser with High Res Stepper Motor


Dates:April 15, 2020

Frames: 180x120" (6h)

Integration: 6h

Avg. Moon age: 22.66 days

Avg. Moon phase: 44.59%


Astrometry.net job: 3421449

RA center: 11h 52' 3"

DEC center: +52° 6' 42"

Pixel scale: 0.683 arcsec/pixel

Orientation: -84.786 degrees

Field radius: 0.697 degrees


Resolution: 6135x4034

Locations: Home Observatory, Pearland, Texas, United States

Data source: Backyard

Description

I had shot this a few weeks ago without inspecting the collimation of my telescope at the time. Collimation was poor, and the resultant image wasn't that great. But I did manage to get out and run through the DSI collimate method for RC scopes, and it improved substantially as the primary mirror was off despite using a Takahashi collimation scope to align the primary and secondary.

I still see some uniform outer corner artifacts on this APSc sensor. I think they could be fixed with a reducer/corrector instead of the CCDT67 telecompressor I'm using right now which doesn't do any correction. Alternatively I could use my ZWO ASI1600 chip, which is smaller and would crop out the artifacts.

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NGC 3953 & NGC 3917 - 8" RC, 



    
        

            Andrew Burwell