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Contains:  M 27, Dumbbell nebula, NGC 6853
Getting plate-solving status, please wait...

M27 in HOO with RGB stars with my little 100mm APO

Technical card

Resolution: 1735x1285

Dates:May 21, 2018June 7, 2018July 7, 2018July 21, 2018

Baader 7nm Ha: 25x600" (gain: 139.00) -20C bin 1x1
Baader 8.5nm OIII: 24x600" (gain: 139.00) -20C bin 1x1
B: 16x30" -20C bin 1x1
G: 13x30" -20C bin 1x1
R: 14x30" -20C bin 1x1

Integration: 8.5 hours

Darks: ~16

Flats: ~16

Flat darks: ~16

Avg. Moon age: 15.46 days

Avg. Moon phase: 47.50%

Bortle Dark-Sky Scale: 5.00

Mean FWHM: 3.10

Temperature: 15.00 job: 2182901

RA center: 299.903 degrees

DEC center: 22.720 degrees

Pixel scale: 1.414 arcsec/pixel

Orientation: 293.334 degrees

Field radius: 0.424 degrees

Data source: Backyard


Hi everyone,

phew that was a tough one. M27 really has a lot of dynamic range and getting it all in a single type of exposure was a challenge. My goal for this image was to figure out whether I could image the faint halo of it with my little APO with enough patience and I can officially report success :)

This is also the first time I have replaced my narrowband stars with RGB ones. Something I plan to do more often from now on.

After doing extensive research into optimal exposures and a lot of math I figured out, that 10m exposures were way too long. I should have used ~3.4m for my total of 5 hours per channel. For 10m exposures to make sense I would have had to shoot a whooping 38h per channel. Well, that's something to know for next time :)



Sven Hoffmann
License: None (All rights reserved)

Sky plot

Sky plot


M27 in HOO with RGB stars with my little 100mm APO, 


            Sven Hoffmann