The Jewel Box Star cluster. The Jewel Box (NGC 4755 at 7,500 light years) in the Southern Hemisphere is one of the youngest known open clusters, about 20 light years across with 198 stars. The stars from Earth are exceptionally beautiful with colors varying from red and yellow, to the more common blue-white with a number of luminous B-type giant stars and a red super giant star. It is also situated near the dark nebula called the Coal Sack. A planet orbiting one of the member stars would have a night sky blazing in brightness with hundreds of stars brighter than Venus or Jupiter at their most brilliant. Several stars may even exceed the brightness of the full moon if we were close enough. These would appear as a dazzling red and several blue stars. The Jewel Box is one of the finest objects in the southern sky.
The Arches star cluster in the center of our galaxy is even more spectacular, and deadly. It contains 150 of the most massive O-type stars crammed into a region only one light year across, with powerful stellar winds that constantly blow through this volume.
An unfortunate planet living in this stellar hotbed would find 150 blue-white stars scattered across the sky about 20 degrees apart, and each shining with the brilliance of the full moon.
The stars would start to go supernova every few million years for a stellar light show unsurpassed anywhere in our galaxy.
The Jewel Box star cluster was first determined by a French astronomer Nicolas Louis de Lacaille when he was doing his South African astrometric observations for his star catalogue. He saw the object as a nebulous cluster due to the small aperture of his telescope, but was the first to recognize it as consisting of many stars.
The name “Jewel Box” was created by an English mathematician, astronomer (and a father of 12 children!) John Herschel, who wrote: “…this cluster, though neither a large nor a rich one, is yet an extremely brilliant and beautiful object when viewed through an instrument of sufficient aperture to show distinctly the very different color of its constituent stars, which give it the effect of a superb piece of fancy jewelry”.