If Ptolemy Had Binoculars

M7 – Ptolemy’s Cluster
Sketch and Details by Carlos Hernandez

I made an observation of M7 (Ptolemy’s Cluster, NGC 6475) in Scorpius on August 10, 2008 (03:00 U.T.). This is a spectacular open cluster, along with M6, located near the tail of Scorpius. On a clear night this cluster may be seen visually as a small “nebula” near the tail of Scorpius, as described by Ptolemy in 130 AD (“nebula following the sting of Scorpius”). Eighty stars brighter than tenth magnitude occupy a region of 1.3 degrees. The cluster lies at a distance between 800 to 1,000 light years. One of the finest open clusters (or any object at that) in the visible in the heavens.

Links;
http://www.hawastsoc.org/deepsky/maps/sco/sco1.gif
http://www.seds.org/messier/m/m007.html
http://apod.nasa.gov/apod/ap050406.html

A digital image produced using Photoshop CS3.

Carlos