NGC 346:小麦哲伦星系内的恒星形成区
2020年12月01日
NGC 346: Star Forming Cluster in the SMC
Image Credit & License: NASA, ESA, Hubble; Processing: Judy Schmidt
Explanation: Are stars still forming in the Milky Way’s satellite galaxies? Found among the Small Magellanic Cloud’s (SMC’s) clusters and nebulas, NGC 346 is a star forming region about 200 light-years across, pictured here in the center of a Hubble Space Telescope image. A satellite galaxy of the Milky Way, the Small Magellanic Cloud (SMC) is a wonder of the southern sky, a mere 210,000 light-years distant in the constellation of the Toucan (Tucana). Exploring NGC 346, astronomers have identified a population of embryonic stars strung along the dark, intersecting dust lanes visible here on the right. Still collapsing within their natal clouds, the stellar infants’ light is reddened by the intervening dust. Toward the top of the frame is another star cluster with intrinsically older and redder stars. A small, irregular galaxy, the SMC itself represents a type of galaxy more common in the early Universe. These small galaxies, though, are thought to be building blocks for the larger galaxies present today.
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NGC 346:小麦哲伦星系内的恒星形成区
影像提供与授权: NASA, ESA, Hubble; 影像处理: Judy Schmidt
说明: 在银河系的伴星系之内,恒星形成活动仍在进行吗?位在这幅哈伯太空望远镜影像中心,宽约200光年的天体,是在小麦哲伦星系内,有众多星团与星云为伴的恒星形成区NGC 346。而作为银河伴星系及南天珍宝之一的小麦哲伦星系(SMC),则位在杜鹃 座方向210,000光年远之处。在探索NGC 346的过程中,天文学家于影像右侧的黝黑交错尘埃带上,找到许多胚胎期恒星。这些仍处在胎衣云塌缩阶段的婴儿期恒星,所发出的星光被周围云气红化,因而外观偏红。此外在影像左上角,还可见到另一个由更年老及更红恒星构成的星团。分类为小型不规则星系的小麦哲伦星系,是早期宇宙较常见的星系,而咸信这种小星系是现今的大星系之构件。
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