NGC 6231 is a young cluster with a estimated age of 3.2 million years. The cluster is quite bright and a nice target for binoculars and any type of telescopes. Its star are gravitationally bounded and gave its compact structure. Also is a good target to image from light polluted places.
The cluster is located at the south-western bend of the Scorpion's tail in the constellation of Scorpius and is approaching us at the speed of 22 kilometres per second.
NGC 6231 was first discovered by Giovanni Batista Hodierna prior to 1654, and later that same year he listed the cluster in his book De Admirandis Coeli Characteribuse published in Palermo, Italy.
The image was taken in April 2011 from my backyard in Martinez; 20 km away from Buenos Aires Argentina. I used a 8" Celestron SCT at f6.3 and a QSI 583 WS riding in a NEQ6. A total exposure time of 80 minutes was used in LRGB (20,20,20,20).