圣诞彗星的彗尾
2021年12月25日
The Tail of a Christmas Comet
Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST) and Lukas Demetz
Explanation: The tail of a comet streams across this three degree wide telescopic field of view captured under dark Namibian skies on December 21. In outburst only a few days ago and just reaching naked eye visibility Comet Leonard (C/2021 A1) is this year’s brightest comet. Binoculars will make the diffuse comet easier to spot though, close to the western horizon after sunset. Details revealed in the sharp image show the comet’s coma with a greenish tinge, and follow the interaction of the comet’s ion tail with magnetic fields in the solar wind. After passing closest to Earth on December 12 and Venus on December 18, Comet Leonard is heading toward perihelion, its closest approach to the Sun on January 3rd. Appearing in late December’s beautiful evening skies after sunset, Comet Leonard has also become known as 2021’s Christmas Comet.
Launch Update: James Webb Space Telescope
Tomorrow’s picture: dawn of a new space telescope/p>
圣诞彗星的彗尾
影像提供与版权: Rolando Ligustri (CARA Project, CAST) and Lukas Demetz
说明: 这幅12月21日摄于纳米比亚幽暗夜空下的3度宽望远镜影像，呈现一颗彗星横贯整个视野的彗尾。在数天前经历爆发之后，李奥纳德（C/2021 A1）成为今年最明亮、裸眼可见的彗星。不过如果借助双筒望远镜，会较容易在日落的西方地平线附近找到这颗弥漫的的彗星。这幅细致的影像，清楚呈现这颗彗星泛绿的彗发，以及其离子尾与太阳风磁场交互作用造就的细微结构。于12月12日通过近地点和12月18日通过近金星点之后，李奥纳德彗星在明年1月3日，会来到最接近太阳的近日点。因为李奥纳德彗星在12月底日落后的天空中绽放光采，故它又有2021年圣诞彗星的美名。
发射消息: 詹姆斯·韦伯太空望远镜
