A Jewel Box of Young Stars
Shining in the heart of the Scorpius constellation, NGC 6231 is a brilliant open star cluster located about 6,500 light years from Earth. Often called the “Northern Jewel Box,” this cluster is filled with hot, massive O- and B-type stars only a few million years old, making it one of the youngest and brightest clusters in our galaxy.
In my image, you can see the dense concentration of these blazing blue-white stars, which are powerful enough to carve out the surrounding dark clouds and illuminate the nearby hydrogen gas that glows red. The cluster spans roughly 15 light years across, and its apparent size in the sky is about 15 arcminutes — half the width of the full Moon.
NGC 6231 is not only a spectacular sight but also an important laboratory for studying stellar evolution, since many of its most massive stars will soon end their lives as supernovae, enriching the interstellar medium for future generations of stars.
Imaged in LRGB and H alpha on my Planewave CDK 700 at Observatorio El Sauce, Chile.
Image acquisition and processing: Mike Selby