A Double Star Cluster in Perseus

Explanation: Few star clusters are this close to each other. Visible to the unaided eye from dark sky areas, it was cataloged in 130 BC by Greek astronomer Hipparchus . Some 7,000 light-years away, this pair of open star cluster s is also an easy binocular target, a striking starfield in the northern constellation of the mythical Greek hero Perseus . Now known as h and chi Persei , or NGC 869 (above right) and NGC 884 , the clusters themselves are separated by only a few hundred light-years and contain stars much younger and hotter than the Sun . In addition to being physically close together, the clusters ' ages based on their individual stars are similar - evidence that both clusters were likely a product of the same star-forming region.