NGC 3766 — the Pearl Cluster

NGC 3766 — click on image to enlarge

NGC 3766 is a colorful open cluster in Centaurus, part of the Carina molecular cloud.  The densest portion of the cluster spans a diameter of 12 arcminutes, slightly less than half the diameter of the full moon. Parenthetically, the moon was “up” during the imaging session, but the cluster is bright enough not to have been significantly affected by the lunar “light pollution” — nevertheless, there was a subtle and complex residual gradient.  Being somewhat of an image processing dinosaur, I have shunned all of the automated (software) methods of gradient removal, and I manually tackled this in Photoshop!

Imaged from SWOS in El Sauce, Chile in April 2023 using a 24″ Planewave CDK @ f/6.5 and SBIG STX-16803. Image scale 0.47″/pixel with about 6 hours of RGB data.  Masters assembled by Stuart Forman. Processing in PixInsight and PS.