美杜莎星云
(原标题: The Medusa Nebula)
2023-03-17
浏览次数: 18
编织和蛇形的发光气体细丝暗示了这个星云的流行名称，美杜莎星云。也被称为Abell 21，这个美杜莎是一个古老的行星状星云，距离双子座约1500光年。就像神话中的同名星云一样，这个星云也伴随着戏剧性的变化。行星状星云阶段代表了像太阳这样的低质量恒星进化的最后阶段，它们从红巨星转变为炽热的白矮星，并在这个过程中摆脱了外层。来自热恒星的紫外线辐射为星云发光提供了动力。美杜莎的转变恒星是靠近整个明亮的新月形中心的那颗暗淡的恒星。在这张深望远镜图像中，较暗的细丝清晰地延伸到明亮新月区域的下方和右侧。据估计，美杜莎星云的直径超过4光年。
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Braided and serpentine filaments of glowing gas suggest this nebula's popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation. The planetary nebula phase represents a final stage in the evolution of low mass stars like the sun as they transform themselves from red giants to hot white dwarf stars and in the process shrug off their outer layers. Ultraviolet radiation from the hot star powers the nebular glow. The Medusa's transforming star is the faint one near the center of the overall bright crescent shape. In this deep telescopic view, fainter filaments clearly extend below and right of the bright crescent region. The Medusa Nebula is estimated to be over 4 light-years across.
© Chesterfield Astronomical Society