参宿七与女巫头星云

2024年10月31日

Rigel and the Witch Head Nebula
Image Credit & Copyright: Simone Curzi

Explanation: By starlight, this eerie visage shines in the dark with a crooked profile evoking its popular name, the Witch Head Nebula. In fact, this entrancing telescopic portrait gives the impression that a witch has fixed her gaze on Orion’s bright supergiant star Rigel. More formally known as IC 2118, the Witch Head Nebula spans about 50 light-years and is composed of interstellar dust grains reflecting Rigel’s starlight. The color of the Witch Head Nebula is caused not only by Rigel’s intense blue light, but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth’s daytime sky to appear blue, although the scatterers in Earth’s atmosphere are molecules of nitrogen and oxygen. Rigel and this dusty cosmic crone are about 800 light-years away. You may still see a few witches in your neighborhood tonight though, so have a safe and Happy Halloween!

Tomorrow’s picture: pixels in space

参宿七与女巫头星云
影像提供与版权: Simone Curzi

说明: 在星光的照耀下，这付怪异的脸谱在夜空中荧荧生辉，而它扭曲如钩的轮廓，为它博得女巫头星云的昵称。在这幅迷人的望远镜影像里，女巫则看似紧盯着猎户座明亮的超巨星参宿七。正式编录号为IC 2118、跨幅超过50光年的的女巫头星云，是一团正在反射参宿七星光的星际尘埃云。而女巫头星云和参宿七周围尘埃的泛蓝色泽，除了是受到参宿七强烈泛蓝星光的直接照耀之外，还有部分源自尘埃微粒散射蓝光的效率高于散射红光。相同的物理过程，也造就了地球白画的蓝天，只不过在地球上，造成散射的粒子是地球大气里的氮和氧分子。参宿七、女巫头星云和它们周围的云气和尘埃，距离我们约800光年远。今晚，你或许会在居家附近看到巫婆，祝你有个安全且快乐的万圣节！

明日的图片: pixels in space