2025年7月29日
A Helix Nebula Deep Field
Image Credit & Copyright: George Chatzifrantzis
Explanation: Is the Helix Nebula looking at you? No, not in any biological sense, but it does look quite like an eye. The Helix Nebula is so named because it also appears that you are looking down the axis of a helix. In actuality, it is now understood to have a surprisingly complex geometry, including radial filaments and extended outer loops. The Helix Nebula (aka NGC 7293) is one of brightest and closest examples of a planetary nebula, a gas cloud created at the end of the life of a Sun-like star. The remnant central stellar core, destined to become a white dwarf star, glows in light so energetic it causes the previously expelled gas to fluoresce. The featured picture, taken in red, green, and blue but highlighted by light emitted primarily by hydrogen was created from 12 hours of exposure through a personal telescope located in Greece. A close-up of the inner edge of the Helix Nebula shows complex gas knots the origin of which are still being researched.
Portal Universe: Random APOD Generator
Tomorrow’s picture: loopy Sun
螺旋星云的深场影像
影像提供与版权: George Chatzifrantzis
说明: 螺旋星云在看你吗？没这回事，至少不是任何生物学上的行为，不过它的确看来很像一只眼睛。它之所以称为螺旋星云，是因为它貌似一个我们顺轴望进去的螺旋。实际上，我们现在知道它具有出奇复杂的几何结构，包括辐条状的云气丝及广袤的外晕。螺旋星云（亦称NGC 7293）是离我们最近最明亮的行星状星云之一，而这团行星状星云则是类太阳恒星在生命末期时，所产生的气体云。星云中心孑遗下来的、注定会成为白矮星的恒星核，则辐射出非常高能量的光，激发先前抛出的气体辐射出荧光。这张摄于红、绿、蓝等波段但以氢辐射的红光为主色的主题影像，建构自一部位于希腊后院的私人望远镜，所累积的12小时长曝光观测数据。针对螺旋星云内缘所进行的细部观测显示，该处有许多来源不明、仍有待研究厘清的复杂云气结。
