行星状星云Abell 7
(原标题: Planetary Nebula Abell 7)
2026-01-23
浏览次数: 1463
非常微弱的行星状星云Abell 7距离我们大约1800光年。它位于猎户座的南面，在地球的天空中，朝向熊座。在这张深望远镜拍摄的照片中，我们可以看到它的直径约为8光年的简单球形，与银河系中分散的恒星合影。通过长时间曝光和捕捉氢原子和氧原子发射的窄带滤光片，在视觉上增强了宇宙云中美丽而复杂的形状。否则，阿贝尔7号就会太微弱而无法被肉眼看到。行星状星云代表了恒星演化的一个非常短暂的最后阶段，我们的太阳将在50亿年后经历这个阶段，因为星云的中心，曾经像太阳一样的恒星摆脱了它的外层。据估计，Abell 7已经有2万年的历史了。但它的中心恒星，在这里看到的是一颗褪色的白矮星，大约有100亿年的历史。
查看原文解释
Very faint planetary nebula Abell 7 is about 1,800 light-years distant. It lies just south of Orion in planet Earth's skies toward the constellation Lepus, The Hare. Posing with scattered Milky Way stars, its generally simple spherical shape about 8 light-years in diameter is revealed in this deep telescopic image. The beautiful and complex shapes seen within the cosmic cloud are visually enhanced by the use of long exposures and narrowband filters that capture emission from hydrogen and oxygen atoms. Otherwise Abell 7 would be much too faint to be appreciated by eye. A planetary nebula represents a very brief final phase in stellar evolution that our own Sun will experience 5 billion years hence, as the nebula's central, once sun-like star shrugs off its outer layers. Abell 7 itself is estimated to be 20,000 years old. But its central star, seen here as a fading white dwarf, is some 10 billion years old.
© Martin Pugh