太空生日照，今天出生的粉丝，生日快乐！
Explanation: While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st century astronomers would identify it as a planetary nebula, but it's not a planet either, even though it may appear round and planet-like in a small telescope. Messier 27 (M27) is an excellent example of a gaseous emission nebula created as a sun-like star runs out of nuclear fuel in its core. The nebula forms as the star's outer layers are expelled into space, with a visible glow generated by atoms excited by the dying star's intense but invisible ultraviolet light. Known by the popular name of the Dumbbell Nebula, the beautifully symmetric interstellar gas cloud is over 2.5 light-years across and about 1,200 light-years away in the constellation Vulpecula. This impressive color composite highlights details within the well-studied central region and fainter, seldom imaged features in the nebula's outer halo. It incorporates broad and narrowband images recorded using filters sensitive to emission from hydrogen and oxygen atoms.
当18世纪的法国天文学家查尔斯·梅西耶在天空中寻找彗星时，他将能判定的肯定不是彗星的天体编录成册。这幅图片就是著名的非彗星名册中的第27号天体。实际上，现在的天文学家将它分类为行星状星云，但它也不是行星，只是我们用小型望远镜观看时，它看起来具有圆形和行星状而已。M27是一个典型的气体发射星云，它是由类似太阳的恒星耗尽其核心燃料后所产生的。当恒星的外层被抛入太空时，外层中的原子受到垂死恒星发出的强烈但不可见的紫外光激发而辐射出可见光，便形成了气体发射星云。这个美丽对称状的星云也被称为哑铃星云，它位于狐狸座，大小约过2.5光年，距离地球约1200光年。这幅令人印象深刻的彩色图像是由使用滤波器拍摄的宽波段和窄波段照片组合而成，记录了氢原子和氧原子发出的辐射。
高清原图地址：
https://apod.nasa.gov/apod/image/1908/m27bigFranke.jpg