NASA·APOD每日天文一图2022.6.27 [超高清]

大神级稀罕星云照：古姆星云

The Gum Nebula is so large and close it is actually hard to see. This interstellar expanse of glowing hydrogen gas frequently evades notice because it spans 35 degrees -- over 70 full Moons -- while much of it is quite dim. This featured spectacular 90-degree wide mosaic, however, was designed to be both wide and deep enough to bring up the Gum -- visible in red on the right. The image was acquired late last year with both the foreground -- including Haba Snow Mountain -- and the background -- including the Milky Way's central band -- captured by the same camera and from the same location in Shangri-La, Yunnan, China. The Gum Nebula is so close that we are only about 450 light-years from the front edge, while about 1,500 light-years from the back edge. Named for a cosmic cloud hunter, Australian astronomer Colin Stanley Gum (1924-1960), the origin of this complex nebula is still being debated. A leading theory for the origin of the Gum Nebula is that it is the remnant of a million year-old supernova explosion, while a competing theory holds that the Gum is a molecular cloud shaped over eons by multiple supernovas and the outflowing winds of several massive stars. 

古姆星云非常大，离我们非常近，实际上很难看到。这片在星际间大面积伸展的发光氢气云经常被忽略，因为它的直径约35度——相当于70多个满月，而其中大部分都相当暗淡。不过，这幅90度宽的壮观拼接照拍得既广角又深度，足以展示出古姆星云，也就是在画面右侧可见的红色。这幅照片是去年晚些时候在中国云南香格里拉拍摄的，前景（包括哈巴雪山）和背景（包括银河）在同一地点用同一台相机拍摄。古姆星云离我们太近了，我们距离它的前缘只有450光年，而距离它的后缘也只有1500光年。这个复杂的星云以一位宇宙云猎人——澳大利亚天文学家科林·斯坦利·古姆（1924-1960）的名字命名，其起源仍有争议。关于古姆星云起源的一个主要理论是，它是百万年前超新星爆炸的残余物；而另一个与之竞争的理论认为，古姆星云是被多重超新星和多颗大质量恒星的外流星风在数十亿年间“塑造”出的分子云。