NGC6888 – Crescent Nebula
The Crescent Nebula, the roughly round thing in the bottom-right if the image, is an emission nebula located in the constellation Cygnus. Its form is due to a the fast stellar wind from a star colliding with and ionizing the slower moving wind ejected by the same star when it became a red giant around 400,000 years ago.
You need a very dark sky to see it and a big telescope. It is very faint and the eyes are not enough sensitive to the red light. There is only one site from where I saw it : the Col de Restefond in south-eat of France. One of the very best astronomy spot in the country. At 2500m high and far from the city lights the sky is awesome and we can see a lot of object better than anywhere else.
27 exposures of 10 minutes.
Camera : Canon EOS 1000D unfiltered
Telescope : Takahashi FSQ-106ED refractor.
Mount : Takahashi EM-200 USD3.
Guiding : Orion Starshoot Autoguider on a William Optic Zenithstar 66SD refractor.
Outside temperature : 2°C
Sensor temperature : 6°C
Software : auto-guiding and acquisition with MaximDL, processing with Iris.
Location : Col de Restefond, France