星际彗星2I鲍里索夫
(原标题: Interstellar Comet 2I Borisov)
2022-03-05
浏览次数: 23
来自银河系其他地方的2I/Borisov彗星刚刚访问了太阳系。2019年8月30日，业余天文学家Gennady Borisov发现了第一颗已知的星际彗星，这是哈勃太空望远镜在2019年11月和12月拍摄的两张图像。在左边，一个遥远的背景星系靠近鲍里索夫的视线，当哈勃望远镜追踪到距离地球约3.27亿公里的高速彗星和尘埃尾巴时，它变得模糊了。在右边，2I/Borisov出现在近日点之后不久，这是它最接近太阳的时候。欧洲南方天文台的观测表明，这颗彗星在2019年通过近日点之前可能从未接近过任何恒星。2019年12月28日，鲍里索夫号最接近我们美丽的星球，距离约2.9亿公里。尽管哈勃望远镜拍摄的清晰图像并不能分辨出彗星的核心，但它们确实得出了彗星直径不到1公里的估计。
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From somewhere else in the Milky Way galaxy, Comet 2I/Borisov was just visiting the Solar System. Discovered by amateur astronomer Gennady Borisov on August 30, 2019, the first known interstellar comet is seen in these two Hubble Space Telescope images from November and December 2019. On the left, a distant background galaxy near the line-of-sight to Borisov is blurred as Hubble tracked the speeding comet and dust tail about 327 million kilometers from Earth. At right, 2I/Borisov appears shortly after perihelion, its closest approach to Sun. European Southern Observatory observations indicate that this comet may never have passed close to any star before its 2019 perihelion passage. Borisov's closest approach to our fair planet, a distance of about 290 million kilometers, came on December 28, 2019. Even though Hubble's sharp images don't resolve the comet's nucleus, they did lead to estimates of less than 1 kilometer for its diameter.