NGC 1850: 银河系找不到的天体

2023年2月20日

NGC 1850: Not Found in the Milky Way
Image Credit: NASA, ESA and P. Goudfrooij (STScI); Processing: M. H. Özsaraç (Türkiye Astronomi Derneği)

Explanation: There is nothing like this ball of stars in our Milky Way Galaxy. This is surprising because, at first glance, this featured image by the Hubble Space Telescope suggests that star cluster NGC 1850’s size and shape are reminiscent of the many ancient globular star clusters which roam our own Milky Way Galaxy’s halo. But NGC 1850’s stars are all too young, making it a type of star cluster with no known counterpart in the Milky Way. Moreover, NGC 1850 is also a double star cluster, with a second, compact cluster of stars visible here just to the right of the large cluster’s center. Stars in the large cluster are estimated to be 50 million years young, while stars in the compact cluster are younger still, with an age of about 4 million years. A mere 168,000 light-years distant, NGC 1850 is located near the outskirts of the Large Magellanic Cloud galaxy. The glowing gas filaments across the image left, like supernova remnants in our own galaxy, testify to violent stellar explosions and indicate that short-lived massive stars have recently been present in the region.

Tomorrow’s picture: double falls

NGC 1850: 银河系找不到的天体
图像提供: NASA, ESA and P. Goudfrooij (STScI); 图像处理: M. H.Özsaraç（Türkiye Astronomi Derneği）

说明: 我们银河系并没有这样的球状星团。这个陈述有点出人意表，因为乍看之下，这幅哈勃太空望远镜主题图像所呈现的星团NGC 1850，其大小和形状，与于我们银河系的银晕中漫游的许多古老球状星团都很相近。然而，NGC 1850的成员星都很年轻，也因此，在我们银河系内找不到可与之对照的星团。除此之外，NGC 1850也是一个双星团，其紧实的伴星团，位于这个大星团的中右方。大星团内的恒星之年龄，据估在5千万年上下，而小星团的恒星更加年轻，大约只有4百万年稚龄。距离只有168,000光年远的NGC 1850，座落在大麦哲伦星系的外围附近。图像左侧的明亮丝状云气，就如同我们银河系内的超新星遗迹一样，见证了狂暴的恒星爆炸事件，也显示此区域直到最近还有生命极短暂的大质量恒星。

明日的图片: double falls