The Double Cluster in Perseus
Image Credit & Copyright: Mårten Frosth
Explanation: This pretty starfield spans about three full moons (1.5 degrees) across the heroic northern constellation of Perseus. It holds the famous pair of open star clusters, h and Chi Persei. Also cataloged as NGC 869 (top) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters are both 13 million years young based on the ages of their individual stars, evidence that they were likely a product of the same star-forming region. Always a rewarding sight in binoculars, the Double Cluster is even visible to the unaided eye from dark locations.
Tomorrow’s picture: light-weekend
影像提供与版权: Mårten Frosth
说明: 这片美丽的星场，涵盖了英仙座约3个满月（1.5度）宽的的区域。此区著名的英仙h与Chi双星团，其编录号分别为NGC 869（上）及NGC 884，二者的距离皆约为7,000光年远，而且成员星也远比太阳炽热且年轻。根据它们成员星的年龄来推断，这对间隔只有数百光年的双星团，年龄皆在1千3百万左右，因此它们可能是诞生于同一个恒星形成区。这对天体是用双筒望远镜巡天的赏心悦目标的，而在低光害地区，甚至连肉眼也可见。