今日天文图片
IC 418：螺旋状星云
(原标题: IC 418: The Spirograph Nebula)
2025-04-27
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是什么创造了IC 418的奇怪纹理？行星状星云IC 418被称为螺旋状星云，因为它与周期性绘图工具的图画相似，它显示出的图案还没有被很好地理解。也许它们与来自可变中心恒星的混乱风有关，它在几个小时内不可预测地改变了亮度。相比之下，有证据表明，仅仅在几百万年前，IC 418可能是一颗与我们的太阳类似的恒星。仅仅几千年前，IC 418可能是一颗普通的红巨星。然而，由于耗尽了核燃料，外层的外壳开始向外膨胀，留下了一个热的残余核心，注定要成为一颗白矮星，在图像中心可见。来自中心核心的光激发了星云周围的原子，使它们发光。IC 418距离我们大约2000光年，直径0.3光年。这张由哈勃太空望远镜拍摄的假彩色图像揭示了不寻常的细节。
查看原文解释
What is creating the strange texture of IC 418? Dubbed the Spirograph Nebula for its resemblance to drawings from a cyclical drawing tool, planetary nebula IC 418 shows patterns that are not well understood. Perhaps they are related to chaotic winds from the variable central star, which changes brightness unpredictably in just a few hours. By contrast, evidence indicates that only a few million years ago, IC 418 was probably a well-understood star similar to our Sun. Only a few thousand years ago, IC 418 was probably a common red giant star. Since running out of nuclear fuel, though, the outer envelope has begun expanding outward leaving a hot remnant core destined to become a white-dwarf star, visible in the image center. The light from the central core excites surrounding atoms in the nebula causing them to glow. IC 418 lies about 2000 light-years away and spans 0.3 light-years across. This false-color image taken from the Hubble Space Telescope reveals the unusual details.