NGC 2158 is an open cluster in the constellation Gemini, half a degree away from the better known M 35. Its components are rather weak, around the twelfth magnitude.
The low luminosity of this cluster is justified by the great distance at which it is located, over 16,000 light years, that is on the outskirts of the Milky Way, on the Cygnus arm; therefore it also appears strongly obscured by interstellar dust which stands in the line of sight.
Optic Celestron C9.25 Edge HD f/10
Mount Losmandy G11 with Ovision worm and FS2
Camera Atik 4000 with Starlight Xpress filter wheel 5 positions
Filters Baader RGB 50.8 unmounted
Guiding system OAG LB Astro Proxima with Lodestar
Exposure details R 10x300" bin1 -20C
G 10x300" bin1 -20C
B 10x300" bin1 -20C
Total integration 2.5h
Acquisition Maxim, PHD2
Processing Maxim, Photoshop CS5
Location Pian dell'Armà (Pavia, Italy)
Date 24 October 2014