小麦哲伦星系

2021年01月05日

The Small Cloud of Magellan
Image Credit & Copyright: José Mtanous

Explanation: What is the Small Magellanic Cloud? It has turned out to be a galaxy. People who have wondered about this little fuzzy patch in the southern sky included Portuguese navigator Ferdinand Magellan and his crew, who had plenty of time to study the unfamiliar night sky of the south during the first circumnavigation of planet Earth in the early 1500s. As a result, two celestial wonders easily visible for southern hemisphere skygazers are now known in Western culture as the Clouds of Magellan. Within the past 100 years, research has shown that these cosmic clouds are dwarf irregular galaxies, satellites of our larger spiral Milky Way Galaxy. The Small Magellanic Cloud actually spans 15,000 light-years or so and contains several hundred million stars. About 210,000 light-years away in the constellation of the Tucan (Tucana), it is more distant than other known Milky Way satellite galaxies, including the Sagittarius Dwarf galaxy and the Large Magellanic Cloud. This sharp image also includes the foreground globular star cluster 47 Tucanae on the right.

Tomorrow’s picture: streaking dunes

小麦哲伦星系
影像提供与版权: José Mtanous

说明: 小麦哲伦星云是什么？其实它是个星系。包括葡萄牙航海探险家麦哲伦和他的船员在内的许多人们，都一直在纳闷南天这团弥漫光斑到底是什么。而麦哲伦和船员在15世纪第一次的环球航行中，就有很充裕的时间探索大多数人不熟悉的南天夜空。也因此，对南天的观星者来说，特别吸睛的两大星空奇观，在西方文明里就称为麦哲伦“星云”。在过去的100年里，研究已证实这二团星云，其实是形状不规则的矮星系，也是我们庞大银河系的伴星系。小麦哲伦星系的真实大小约为15,000光年，拥有数亿颗成员星。小麦哲伦星系位在杜鹃座方向约210,000光年远之处，在已知的银河伴星系之中，比人马矮星系以及大麦哲伦星系要远。这幅清晰的影像，同时也记录了右侧位在前景的球状星团杜鹃座47。

明日的图片: streaking dunes