Contains: M 39, NGC 7092
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M39 Open Star Cluster in Cygnus

Technical card

Resolution: 3266x2770

Dates: Oct. 1, 2017

Blue: 30x60" bin 1x1
Green: 23x60" bin 1x1
Ha 3nm: 17x600" bin 2x2
Red: 30x60" bin 1x1

Integration: 4.2 hours

Avg. Moon age: 10.46 days

Avg. Moon phase: 80.45%

Bortle Dark-Sky Scale: 8.00

Mean SQM: 18.50 job: 1769090

RA center: 323.072 degrees

DEC center: 48.359 degrees

Pixel scale: 1.435 arcsec/pixel

Orientation: 359.945 degrees

Field radius: 0.854 degrees

Locations: The Hills Observatory, Manchester, United Kingdom


The first image is how you would normally see the cluster in RGB
The second is with an extra 17 x 600s bin2x2 exposures added.

As far as I know this could be the first time M39 has been shown against a backdrop of Ha nebulosity. The Ha is pretty faint and has to be pushed a bit to get it out of the noise.

The image started out as a quick image in RGB taken in less than 90 mins, very quick for me and I wanted to demonstrate that you don't have to take long exposures to get some great looking images.

When I was processing the image I could see that there are areas of dust and I took it further to try and show this better. I tried a Ha filter which seemed to work, so took some more.



Mike Oates



With Ha added

Sky plot

Sky plot


M39 Open Star Cluster in Cygnus, 


        Mike Oates