Messier 103 is an open cluster located in constellation Cassiopeia. With its distance 8500 light-year from Earth, this cluster is one of the most distant clusters from Messier’s catalogue.

The picture is a stack of 56 pictures, each 2 minutes long, i.e. nearly two hours of integration time. December is a month, which is rich with deep space objects, but it’s also rich with clouds. In whole December I got only single opportunity to take my telescope outside, therefore this is not the only deep space object, which I captured this night.

Technical details:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length1000 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-20°C
CorrectorTS-Optics 2" 3-element MaxField
FiltersHutech IDAS LPS-D2
Exposure56x120s, Gain 94, bin 1x1,
Date2018-12-13