科普阅读:Astronomy Picture of the Day(08-16-2011)
日期:2011-08-16 17:27

(单词翻译:单击)

Shapley 1: An Annular Planetary Nebula

What happens when a star runs out of nuclear fuel? For stars about the mass of our Sun, the center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, pictured above and designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure. Although some of these nebulas appear like planets on the sky (hence their name), they actually surround stars far outside our Solar System.

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重点单词
  • massn. 块,大量,众多 adj. 群众的,大规模的 v.
  • particularadj. 特殊的,特别的,特定的,挑剔的 n. 个别项目
  • designatedadj. 特指的;指定的
  • apparentadj. 明显的,表面上的
  • planetaryadj. 行星的,有轨道的
  • atmosphericadj. 大气的,大气层的,制造气氛的
  • dwarfn. 矮子,侏儒 vt. 使矮小 vi. 变小
  • astronomern. 天文学家