My god, it is full of stars! I think everybody knows this sentence and if not, you should watch probably the best movie from Stanley Kubrick 2001: A Space Odyssey (1968). Anyway, my reaction when I processed this image was the same just like David Bowman, when he was traveling through the star gate created by the monolith orbiting the Jupiter. The reason why there are so many stars in the background is simple. M39 is an open cluster located in not far from constellation Cygnus (Swan). This constellation is lying on the plane of our home galaxy Milky Way, therefore we are now looking through the galactic disk.

m39-opencluster-2016-09-29-30c-31l-200s-13rgb-120sb2x2-fl1000

Telescope:Newton 254/1000 mm
Aperture:254 mm
Focal length:1000 mm
Mount:Gemini GF53f
Autoguiding:ZWO 174MM, TS 60/240 mm
Camera:Moravian instruments G2 8300M @-30C
Corrector:GPU
Filters:Baader LRGB
Exposure:31xL 180 s bin 1x1, 13RGB, 120s, bin 2x2
Date:2016-09-29