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Contains:  M 15, NGC 7078
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M15 Globular Cluster, 





    
        

            ashley
M15 Globular Cluster

M15 Globular Cluster

Technical card

Resolution: 3372x2698

Dates:Oct. 31, 2014

Frames: 29x15" ISO1600 31C

Integration: 0.1 hours

Darks: ~30

Flats: ~25

Bias: ~21

Avg. Moon age: 7.79 days

Avg. Moon phase: 54.32%

Bortle Dark-Sky Scale: 8.00

Temperature: 18.00

Astrometry.net job: 402757

RA center: 322.505 degrees

DEC center: 12.205 degrees

Orientation: -115.797 degrees

Field radius: 0.294 degrees

Locations: Home Observatory, Tampa, Florida, United States

Description

This is the result of testing longer exposures on my unguided mount. I actually took about 143 or so 15" subs, but only 29 of them were usable—which is precisely why I opt for shorter exposures. With 6" subs, I can expect roughly 80% of them to be usable, where as the 15" ones appear to be around 20%.

So anyway, doing the math... with 6" subs I can roughly assume that of the 143… 114 would be usable. That comes out to a 11.4 minute integration time, where as with the 15" ones, I got a 7.25 minute integration time—and less frames to stack. So it seems like until I can get a more precise mount I should still opt for shorter exposures, unless I can capture 500 or 600 of the 15" subs.

Anyway, hopefully this won't matter soon, because in the near future I plan on getting a GEM so exposure time is a non issue for me.

Comments

Author

ashley
ashley
License: None (All rights reserved)
2140
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Revisions

  • M15 Globular Cluster, 





    
        

            ashley
    Original
  • Final
    M15 Globular Cluster, 





    
        

            ashley
    B

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Histogram

M15 Globular Cluster, 





    
        

            ashley