天极[Celestial Pole] - 达人(其实～我是卧底，来自外星)

2005/07/16 | 天极[Celestial Pole]
类别(¤〖天文〗) | 评论(0) | 阅读(31) | 发表于 20:31: The celestial poles are the projections of the Earth's north and south poles into the celestial sphere. Because of precession of the equinoxes, these poles wander along a circle with a period of about 26,000 years. Though Polaris is currently the closest bright star to the north celestial pole (a.k.a. the North Star), Vega will be the closest around A.D. 14,000.; 0

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