星团M35和ngc2158
(原标题: Star Clusters M35 and NGC 2158)
2021-05-10
浏览次数: 38
星团可以近也可以远，可以年轻也可以年老，可以分散也可以紧密。这张特色图像显示了同一区域内两个截然不同的疏散星团。左下角的M35相对较近，距离我们2800光年，相对年轻，只有1.5亿年的历史，而且相对分散，大约有2500颗恒星分布在30光年宽的体积上。明亮的蓝色恒星经常区分出M35这样的年轻疏散星团。相比之下，右上方的NGC 2158距离M35的4倍，年龄是M35的10倍以上，而且更加致密。NGC 2158明亮的蓝色恒星已经自我毁灭，星团的光线被更老的黄色恒星所主导。一般来说，疏散星团是在我们银河系的平面上发现的，包含100到1万颗恒星——所有这些恒星几乎是在同一时间形成的。疏散星团M35和NGC 2158可以用小型望远镜朝双子星座方向观测。
查看原文解释
Clusters of stars can be near or far, young or old, diffuse or compact. The featured image shows two quite contrasting open star clusters in the same field. M35, on the lower left, is relatively nearby at 2800 light years distant, relatively young at 150 million years old, and relatively diffuse, with about 2500 stars spread out over a volume 30 light years across. Bright blue stars frequently distinguish younger open clusters like M35. Contrastingly, NGC 2158, on the upper right, is four times more distant than M35, over 10 times older, and much more compact. NGC 2158's bright blue stars have self-destructed, leaving cluster light to be dominated by older and yellower stars. In general, open star clusters are found in the plane of our Milky Way Galaxy, and contain anywhere from 100 to 10,000 stars -- all of which formed at nearly the same time. Both open clusters M35 and NGC 2158 can be found together with a small telescope toward the constellation of the Twins (Gemini).
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