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Contains:  NGC 7217
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NGC 7217 - A galaxy in Pegasus, 





    
        

            Daniel.P
NGC 7217 - A galaxy in Pegasus

NGC 7217 - A galaxy in Pegasus

Technical card

Resolution: 2810x1858

Dates:Aug. 6, 2016Aug. 9, 2016Aug. 11, 2016

Frames: 48x900" -15C bin 1x1

Integration: 12.0 hours

Darks: ~7

Flats: ~5

Bias: ~50

Avg. Moon age: 5.95 days

Avg. Moon phase: 36.29%

Mean SQM: 21.20

Mean FWHM: 2.10

Temperature: 18.00

Astrometry.net job: 1245495

RA center: 331.959 degrees

DEC center: 31.353 degrees

Pixel scale: 0.762 arcsec/pixel

Orientation: 177.806 degrees

Field radius: 0.356 degrees

Locations: Duc, Prayssas, Lot et Garonne, France

Description

FWHM measured in PI : 2.1 arcsec (Moffat 4) : the seeing was quite good on average, ranging between 3.0 to 1.6 arcsec on sub exposures

Equipment used :
first night : AO with OAG
2nd & 3rd nights : AO + ONAG (on axis guiding)

With the ONAG, the 133 mm back focus was not achieved (+/- 170 mm) ; slight increase in FWHM on the external part of the image can be detected. I am working on achieving exact BF.

I will publish map of FWHM with unadjusted BF for information.

The combination of AO & ONAG is very effective and easy to use. I still have some trouble tuning the "bump" parameter in PHD, but OK overall.

Pre-processing done in Pixinsight :
- overscan area offset correction
- bias correction
- dark correction using 7 x 1800 s darks
- flat correction
- hot pixel correction
- debayer
- registration
- stack
- crop
Processing done in Pixinsight :
- backgroung color neutralisation
- color calibration using galaxy
- sky background removal (DBE in PI)
- slight deconvolution
- non linear image creation
- TGV denoise (no mask)
- color saturation boost masked
- green neutral
Final image :
- jpeg calibration done in Mac Photo (levels adjust and further saturation boost and color balance)

Comments

Author

Daniel.P
Daniel.P
License: None (All rights reserved)
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NGC 7217 - A galaxy in Pegasus, 





    
        

            Daniel.P