又是一期絕美星云！

Supergiant star Gamma Cygni is at the center of the Northern Cross. Near the plane of our Milky Way galaxy, that famous asterism flies high in northern summer night skies in the constellation Cygnus the Swan. Known by the proper name Sadr, Gamma Cygni also lies just below center in this telescopic skyscape, with colors mapped from both broadband and narrowband image data. The field of view spans about 3 degrees (six Full Moons) on the sky and includes emission nebula IC 1318 and open star cluster NGC 6910. Filling the upper part of the frame and shaped like two glowing cosmic wings divided by a long dark dust lane, IC 1318’s popular name is understandably the Butterfly Nebula. Right of Gamma Cygni, are the young, still tightly grouped stars of NGC 6910. The distance to Gamma Cygni is around 560 parsecs or 1,800 light-years. Estimates for IC 1318 and NGC 6910 range from 2,000 to 5,000 light-years.

超巨星天津一位在”北十字”的中心。而這個著名的星官則座落在銀河系盤面附近，位在夏季北半球夜空高懸的天鵝座之內(nèi)。在這幅由窄與寬波段濾鏡數(shù)據(jù)整合而成的彩色望遠(yuǎn)鏡影像里，英文專名為Sadr的天津一，位在這片星野的中心下方。這幅涵蓋約3度（6個滿月）天區(qū)的影像，所記錄的天體還包括發(fā)射星云IC 1318和疏散星團(tuán)NGC 6910。占據(jù)視野頂端、形似2片宇宙級發(fā)光翅膀、為一道頎長黝黑塵埃帶所分隔的IC 1318 ，并不難理解為何其俗名為蝴蝶星云。在天津一右方，可見到年輕仍緊密聚集的NGC 6910之成員星。天津一的距離約為560秒差距（1,800光年）。而IC 1318和NGC 6910的估計距離，則介于2,000到5,000光年之間。 （Gamma Cygni 天津一）