Tag: Messier7

M7 Ptolemy cluster

Messier 7, sometimes called the Ptolemy Cluster, is an open cluster located in between constellations Sagittarius and Scorpius. The cluster is visually located on the galactic plane of the Milky Way, therefore there are many stars in the background. The cluster is badly visible from Central Europe. Much better opportunities to observe or photograph this cluster have astronomers or astrophotographers in southern countries. My last attempt to capture it in Greece was constantly disturbed by the weather, therefore when I was again in the South, specifically at Fuerteventura, I didn’t hesitate and recapture this beautiful cluster.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
Exposure64x180s, Gain 94, bin 1x1,

M7 Ptolemy Cluster

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,