2025年10月1日
NGC 6960: The Witch’s Broom Nebula
Image Credit & Copyright: Brian Meyers
Explanation: Ten thousand years ago, before the dawn of recorded human history, a new light would suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was from a supernova, or exploding star, and record the expanding debris cloud as the Veil Nebula, a supernova remnant. This sharp telescopic view is centered on a western segment of the Veil Nebula cataloged as NGC 6960 but less formally known as the Witch’s Broom Nebula. Blasted out in the cataclysmic explosion, an interstellar shock wave plows through space sweeping up and exciting interstellar material. Imaged with narrow band filters, the glowing filaments are like long ripples in a sheet seen almost edge on, remarkably well separated into atomic hydrogen (red) and oxygen (blue-green) gas. The complete supernova remnant lies about 1400 light-years away towards the constellation Cygnus. This Witch’s Broom actually spans about 35 light-years. The bright star in the frame is 52 Cygni, visible with the unaided eye from a dark location but unrelated to the ancient supernova remnant.
Tomorrow’s picture: the shadowy realm
NGC 6960: 女巫的扫帚星云
影像提供与版权: Brian Meyers
说明: 大约一万年前，在人类有文字记录之前的时代，夜空中忽然出现了一道新的光亮，仅仅维持了几周就消失了。今天我们知道，那其实是一颗超新星──也就是恒星爆炸时所发出的光。如今，我们能够在天空中看到它残留下来的巨大气体云，也就是著名的「面纱星云」（Veil Nebula），这是一个超新星遗迹。这张望远镜影像，对准的是面纱星云西侧的一部分，在星表上编录为NGC 6960，但更常被称为「女巫扫帚星云」。在那场惊天动地的爆炸中，猛烈的震波向外推进，横扫并激发了星际间的物质。透过窄波段滤镜拍摄，我们可以看到纤细发光的丝状结构，就像是一大片薄膜的涟漪，侧面呈现在我们眼前，并且清楚分离为不同的元素：红色来自氢原子，蓝绿色则来自氧原子。整个超新星残骸距离地球约1,400光年，位于天鹅座（Cygnus）的方向。单就「女巫扫帚」这一段的长度，其跨度约有35光年。画面中那颗明亮的恒星名叫52天鹅座（52 Cygni），在暗黑的天空下肉眼可见，但其实与这个古老的超新星残骸并没有关联。
明日的图片: the shadowy realm
