三个星系与一颗彗星

2023年12月21日

Three Galaxies and a Comet
Image Credit & Copyright: Dan Bartlett

Explanation: Distant galaxies abound in this one degree wide field of view toward the southern constellation Grus (The Crane). But the three spiral galaxies at the lower right are quite striking. In fact, all three galaxies are grouped about 70 million light years away and sometimes known as the Grus Triplet. They share the pretty telescopic frame, recorded on December 13, with the comet designated C/2020 V2 ZTF. Now outbound from the inner Solar System and swinging below the ecliptic plane in a hyperbolic orbit, the comet was about 29 light-minutes from our fair planet in this image. And though comet ZTF was brighter when it was closest to the Sun last May and closest to Earth in September of 2023, it still shines in telescopes pointed toward southern night skies, remaining almost as bright as the Grus Triplet galaxies.

Tomorrow’s picture: solstice solargraphy

三个星系与一颗彗星
影像提供与版权: Dan Bartlett

说明: 在这片宽达1度、远眺南天天鹤座方向的宽广视野里，到处都是遥远的星系。其中，位于右下角的三个星系格外出采。这3个所聚成的、偶有天鹤三重星系之称的小星系群，离我们大约有7千万光年远。于12月13日拍下这张美丽的望远镜影像之时，它们与彗星C/2020 V2 ZTF共享了这片视野。这颗沿双曲线轨道逐渐远离太阳系内围，同时往黄道面下方沉降的彗星，当时距离地球约29光分。想当然耳，这颗彗星在2023年5月最接近太阳及2023年9月最接近地球时，肯定比拍下此照时要明亮多了，不过于眺望南天夜空的望远镜里，其亮度依然和天鹤三重星系很接近。

明日的图片: solstice solargraphy