Blue diamonds on a golden carpet
Messier 7, The Ptolemy Cluster in Scorpius
Diamonds of Namibia. Brillant gems on the sand of Namib Desert.
This image shows Messier 7 (NGC 6475) also known as the Ptolemy Cluster, is a bright open cluster in Scorpius constellation. It lies at an approximate distance of 1000 light years from Earth. The cluster is the southernmost Messier object in the sky, which makes it a challenging target for those in northern latitudes as Scorpius constellation never rises very high above the horizon. But with a visual magnitude of 3.3 and an apparent diameter of 80 arc minutes it can be seen even with naked eye from a dark northern observing site, but a small pair of binoculars show easily.
This photograph was taken from Namibia, where the cluster was overhead, high in the sky, during perfect observing conditions.
- 200/750 Newton, 3" Wynne (710mm effective focal length)
- QSI 683 WSG-8, LRGB filters
- SkyWatcher EQ6 + Boxdörfer DynoStar
- Off axis, Lacerta-MGen autoguider + Mgen2Maxim
- Exposure time, filters:
- 50 min RGB
- Location, date:
- Hakos astrofarm, Namibia (1835m); 2016 May
- Observing conditions:
- Transparency: 10/10, Seeing: 10/10
- ImagesPlus, Registar, Photoshop