M 17 (Omega Nebula), M 18

M 17 (Omega Nebula)

An emission nebula in constellation Sagittarius about 5000 to 6000 light years from earth.

May stars being born in these clouds, the brightest and largest are powering this reddish glow of mainly hydrogen gas. Would be an ideal target for narrow band filter, but I tries it without filter, which sometimes reveals dust and reflection nebula.
M 18 is the open star cluster on the bottom, a bit closer to us, just some 4600 light years. It still contains bright blue stars which did not yet go supernova … so the cluster is probably pretty young, not more than 30 million years old.
The image also contains a few other objects as Sh2-47, the small red nebulosity on the top right and a tiny reflection nebula vdB 121 just above M18 on the bottom.
These objects are pretty low above the horizon for me and only accessible during these short nights.

Celestron RASA 11 v2
Celestron CGX-L mount
RisingCam ATR3CMOS26000KPA
Optolong UV/IR Cut filter
Bortle 4-5
No moon
Exposures: 232x30sec (1h56m)


M 17 (Omega Nebula)