The Double Cluster of Perseus is a pair of very bright open clusters, visible in the homonymous constellation of Perseus; they are also known as h and χ Persei or NGC 869 and NGC 884.
Both clusters are found in the Arm of Perseus, the spiral arm of the Milky Way immediately outermost from ours, the Arm of Orion.
In the image shown here, NGC 869 is the cluster in the upper part, while NGC 884 is the one in the lower part; their distance is 6800 light years and 7600 light years respectively.
Optic Tecnosky Apo Refractor 115 - 800mm f/6.9
Mount 10Micron GM1000 HPS
Camera Atik 4000 with Starlight external filter wheel 5 positions
Filters Baader RGB 50.8 unmounted
Guiding system OAG Starlight Xpress with Lodestar
Exposure details R 5x300" bin1 -20C
G 5x300" bin1 -20C
B 5x300" bin1 -20C
Total integration 1.2h
Acquisition Maxim, PHD2
Processing Maxim DL, Photoshop CS5
Location Cegni (Pavia, Italy)
Date 15 November 2015