星尘与彗尾

2022年8月20日

Stardust and Comet Tails
Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST)

Explanation: 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 2×3 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.

Tomorrow’s picture: cosmic crustacean

星尘与彗尾
影像提供与版权: Rolando Ligustri (CARA Project, CAST)

说明: 在往12月19日最靠近太阳的近日点前进之旅途里，彗星C/2017 K2（PanSTARRS 泛星）目前在天蝎座内飞掠，依旧是望远镜观星者巡天的好标的。在摄于8月18日的这幅深空影像里，彗星目前曳着泛绿的彗发、白色的颀长尘尾和短短的离子尾。此外，在这片2×3度宽的视野里，还可见到不停反射蓝色星光的部分尘埃星云IC 4592。亦称为蓝马头星云的IC 4592，距离我们约400光年远，而这颗彗星则离我们不到17光分。初发现之时，来自遥远欧特云、首次造访太阳系内围的新彗星C/2017 K2，在前往内太阳系的处女航途中，还远在土星轨道的外头。

明日的图片: cosmic crustacean