弗莱明三角星云
2023年11月21日
Fleming’s Triangular Wisp
Image Credit & Copyright: Cristiano Gualco
Explanation: These chaotic and tangled filaments of shocked, glowing gas are spread across planet Earth’s sky toward the constellation of Cygnus as part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star. Light from the original supernova explosion likely reached Earth over 5,000 years ago. The glowing filaments are really more like long ripples in a sheet seen almost edge on, remarkably well separated into the glow of ionized hydrogen atoms shown in red and oxygen in blue hues. Also known as the Cygnus Loop and cataloged as NGC 6979, the Veil Nebula now spans about 6 times the diameter of the full Moon. The length of the wisp corresponds to about 30 light years, given its estimated distance of 2,400 light years. Often identified as Pickering’s Triangle for a director of Harvard College Observatory, it is perhaps better named for its discoverer, astronomer Williamina Fleming, as Fleming’s Triangular Wisp.
Tomorrow’s picture: open space
弗莱明三角星云
影像提供与版权: Cristiano Gualco
说明: 这些位在地球天空中的天鹅座方向，外观紊乱纠结的激震明亮云气丝，为面纱星云之一部分。面纱星云本身则为大型的超新星遗迹，是大质量恒星爆炸死亡所产生的扩张碎片云。来自这例超新星爆炸的光，可能在5,000多年前传到地球。而此剧变事件激发的星际激震波，犁过太空扫集并激发星际物质。这些明亮云气丝其实较像是近乎侧向的物质层内之长长涟漪，而在空间上也非常精采的分成电离氢（红）与电离氧（蓝）等辐射层。亦名为天鹅环或NGC 6979的面纱星云，现在的跨幅将近有3度或6个满月的宽度。以此云气丝大约2,400光年的距离来换算，其长度约有30光年。这片云气丝亦名为皮克林三角星云（皮克林为哈佛学院天文台的前主任），不过因其发现者为天文学家威廉敏娜·弗莱明，所以更常见的称号为弗莱明三角星云。 （Pickering’s Triangle 皮克林三角星云； Fleming’s Triangular Wisp 弗莱明三角星云）
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