Messier 23 is an open cluster located in constellation Sagittarius not far from the star Polis (µ Sgr). Visually it’s surrounded in rich star field, because in this direction are located star clouds of Milky Way. The cluster contains approximately 150 confirmed members and it’s about 2000 light-years away from the Solar System.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length660 mm
MountiOptron CEM25P
AutoguidingQHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM
CameraZWO 071 Pro @-10C
CorrectorExplore Scientific HR coma corrector
FiltersAstronomik L-1 - UV IR Block Filter
Exposure23x120s, Gain 134, bin 1x1,
Date2018-09-13