My next holiday target was pretty classical – Cygnus constellation (Swan) narrowband widefield, that in the late summer rises high up to the zenith (in Europe). I framed area starting from the Sadr star (Gamma Cygni) till Tulip nebula. Well known Crescent nebula landed in this configuration nearby frame center. And also Crescent is the most prominent nebulosity fragment in this frame. Whole frame is hydrogenic red, because I collected also some narrowband frames. I had no high hopes about oxygen iii signal, but among well defined Crescent and faint Tulip there is also some nice arc-shaped oxygen patch below the frame center. It is indicated in Interstellarum atlas as O region, but without any symbol 🙁
Image below is composition of 150 minutes of Ha, 150 minutes of Oiii and 24 minutes of each RGB. Using Samyang 135/2 lens, QHY163M camera and Smart EQ Pro mount. Location: Anticiana, Toscana.
I also spent some time on removing stars from this image, so nebular structures could be better defined. It was not trivial task, since stars are all over the frame, and there are bazillions of them. But I managed somehow, and here you can see Crescent floating in the hydrogen see:
And last image is with narrowband filter stars – there are fewer of them, and they are smaller, but colorless 🙂
PS – this image was chosen as Image of The Day on 25.01.2018 on AstroBin portal: