M7 20th June 2015
The second attempt at M7, this time using the RC6
M7 30 May 2015
Ptolemy’s Cluster (NGC6475), located in Scorpius.
M7
Ptolemy’s cluster, also designated NGC6475, is an open cluster located in the Scorpius region (near the “stinger” of the asterism) with an estimated distance of 980 ly and diameter of 25 ly containing the equivalent of 735 solar masses. With an apparant magnitude of +3.3 it is readily detectable by naked eye and has been known since antiquity, first recorded by Ptolemy in 130AD. At a declination of -34.8 degrees it is the most southerly Messier object.