Astronomy Picture of the Day——天鹅座
Cygnus Skyscape
Image Credit & Copyright: Alistair Symon
Explanation: In brush strokes of interstellar dust and glowing hydrogen gas, this beautiful skyscape is painted across the plane of our Milky Way Galaxy near the northern end of the Great Rift and the const ellation Cygnus the Swan. Composed with three different telescopes and about 90 hours of image data the widefield mosaic spans an impressive 24 degrees across the sky. Alpha star of Cygnus, bright, hot, super giant Deneb lies near top center. Crowded with stars and luminous gas clouds Cygnus is also home to the dark, obscuring Northern Coal Sack Nebula, extending from Deneb toward the center of the view. The reddish glow of star forming regions NGC 7000, the North America Nebula and IC 5070, the Pelican Nebula, are just left of Deneb. The Veil Nebula is a standout below and left of center. A supernova remnant, the Veil is some 1,400 light years away, but many other nebulae and star clusters are identifiable throughout the cosmic scene. Of course, Deneb itself is also known to northern hemisphere skygazers for its place in two asterisms -- marking the top of the Northern Cross and a vertex of the Summer Triangle.
天鹅座的天空影像
这幅美丽的影像以星际尘埃和炽热气体为线条，描绘了位于大暗隙北端和天鹅座附近的银河系盘面。这幅宽视场图像是由三张不同的望远镜照片和拍摄时长约90个小时的影像数据结合而成，覆盖了天空中24度的区域。明亮炽热的超巨星天津四（天鹅座的阿尔法星）位于影像中心顶部附近。天鹅座内交织着恒星和发光气体云，也是黑暗、模糊的北方煤袋星云的家园，从天津四朝影像中心方向延伸。红色恒星形成区NGC 7000、北美星云、IC 5070和鹈鹕星云都位于天津四的左侧。面纱星云则位于影像中心左下方，是一个超新星遗迹，距离地球约1400光年，但在整个宇宙场景中，我们还可以辨认出许多其他的星云和星团。当然，天津四本身也被北半球的天文观测者所熟知，因为它位于两个星群中，分别是北十字星的顶部和夏季大三角的顶点。
参考文献：
https://apod.nasa.gov/apod/image/1907/CygnusMosaic07192000Symon.jpg
近期文章：
Astronomy Picture of the Day—阿尔卑斯上空的猎户