Similar to M6, there is another bright open cluster in constellation Scorpius called Ptolemy Cluster or Messier 7. The cluster was discovered very long time ago (130 BC) by Greek astronomer Klaudios Ptolemaios. It belongs to one of the brightest and the biggest star clusters, which are visible by naked eye, but not from Central and Northern Europe.  The open cluster M7 consists of several hundreds of blue stars and it’s approximately 1000 light-year away from Solar System. The background illuminates our home galaxy Milky Way.

To capture this cluster was quite tricky. First two attempts were interrupted by windy and cloudy weather. During the third one I managed to expose 17x 120s and 8x 180s, i.e. 58 minutest in total.

Technical details:

Telescope:Newton 150/600 mm
Aperture:150 mm
Focal length:660 mm
MountiOptron CEM25P
AutoguidingQHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM
Camera:ZWO 071 Pro @-10C
Corrector:Explore Scientific HR coma corrector
Filters:Astronomik L-1 - UV IR Block Filter
Exposure17x120s, 8x180s, Gain 134, bin 1x1,