星尘和彗尾
(原标题: Stardust and Comet Tails)
2022-08-20
浏览次数: 15
12月19日，彗星C/2017 K2 （PanSTARRS）在天蝎座扫过地球的天空时，正在接近太阳，或近日点，望远镜观测者仍然可以看到它。在这张8月18日拍摄的深度图像中，这颗彗星目前呈现出绿色的彗发、长长的白色尘埃尾巴和短离子尾巴。2x3度的宽视场包括了反射蓝色星光的尘埃星云IC 4592的一部分。IC 4592也被称为蓝马头星云，距离我们大约400光年，而彗星距离我们不到17光分。K2首次被发现是在土星C/2017轨道之外的距离，它是一个来自遥远奥尔特云的原始访客，正在向太阳系内部进行首次航行。
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Heading for its closest approach to the Sun, or perihelion, on December 19 comet C/2017 K2 (PanSTARRS) remains a sight for telescopic observers as it sweeps through planet Earth's skies in the constellation Scorpius. The comet currently sports a greenish coma, long whitish dust tail, and short ion tail in this deep image from August 18. The 2x3 degree wide field of view includes part of the dusty nebula IC 4592 reflecting blue starlight. Also known as the Blue Horsehead Nebula, IC 4592 is about 400 light-years distant while the comet is just under 17 light-minutes away. First spotted at a distance well beyond the orbit of Saturn C/2017 K2 is on its maiden voyage to the inner solar system, a pristine visitor from the remote Oort cloud.
© C/2017 K2 (PanSTARRS) remains a sight