October 30, 2009
The Abbé Nicolas-Louis de Lacaille was the first to find this cluster of stars, in 1751 while on an astronomical expedition to the Cape of Good Hope (South Africa). The Kappa Crucis Cluster (NGC 4755), which resides near the Southern Cross, received the nickname the “Jewel Box” during the next century, when astronomer John Herschel viewed it through his telescope and saw the stars were different colors—pale blue and orange. He wrote: “The stars which compose it, seen in a telescope of diameter large enough to enable the colours to be distinguished, have the effect of a casket of variously coloured precious stones.”
We now know that the cluster is about 6,400 light-years away from Earth and around 16 million years old. The stars in the Jewel Box all formed from the same cloud of dust and gas, are about the same age and have similar chemical compositions. The image above was taken recently with MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile. Scientists use clusters like this one to study the evolution of stars. (Image credit: ESO. Click here to find additional images of the cluster, including one from the Hubble Space Telescope.)
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