M 103 is a small open cluster visible in the central part of the Cassiopeia constellation.
It is one of the furthest open clusters listed in the Catalog of Messier, lying at about 2880 parsecs (9400 light years) from the Earth, in a remote corner of the Arm of Perseus.
It has an apparent diameter of 6 arc minutes which, considering the distance, corresponds to a real diameter of 15 light years.
Optics Tecnosky Apo Refractor LT 130 - 910mm f/7
Mount 10Micron GM2000 HPSII
Camera Moravian G3-16200 with external filter wheel 7 positions
Filters Baader RGB 50.8 unmounted
Guiding system OAG Moravian M68 with guide camera Moravian G1-0301
Exposure details R 10x300" bin1 -20C
G 8x300" bin1 -20C
B 10x300" bin1 -20C
Total integration 2.3h
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5
Location Promiod (Aosta Valley, Italy), own remote observatory
Date 8/10 September 2018