2025年2月27日
Open Star Clusters M35 and NGC 2158
Image Credit & Copyright: Evan Tsai, LATTE: Lulin-ASIAA Telescope
Explanation: Framed in this single, starry, telescopic field of view are two open star clusters, M35 and NGC 2158. Located within the boundaries of the constellation Gemini, they do appear to be side by side. Its stars concentrated toward the upper right, M35 is relatively nearby, though. M35 (also cataloged as NGC 2168) is a mere 2800 light-years distant, with 400 or so stars spread out over a volume about 30 light-years across. Bright blue stars frequently distinguish younger open clusters like M35, whose age is estimated at 150 million years. At lower left, NGC 2158 is about four times more distant than M35 and much more compact, shining with the more yellowish light of a population of stars over 10 times older. In general, open star clusters are found along the plane of our Milky Way Galaxy. Loosely gravitationally bound, their member stars tend to be dispersed over billions of years as the open star clusters orbit the galactic center.
Tomorrow’s picture: pixels in space
疏散星团M35与NGC 2158
影像提供与版权: Evan Tsai, LATTE: Lulin-ASIAA Telescope
说明: 在这片望远镜视野里，可见到M35及NGC 2158这二个疏散星团。位于双子座内的它们看似相邻，但其实相距颇远。座落在右上角的M35（亦称NGC 2168），距离我们约2,800光年远，它的400多颗成员星分布在约30光年宽的范围里。像M35这类的年轻疏散星团，通常拥有许多明亮的蓝色恒星，从而可估计出它的年龄约为1.5亿年。左下角的NGC 2158，则比M35远4倍，而且更加紧实，其成员星的年龄比M35内的同类大10倍以上，是以NGC 2158散发的辉光偏黄。一般而言，疏散星团主要分布在银河系的盘面上。疏散星团的成员星受到的重力束缚相对微弱，因此随着疏散星团绕行银河中心，在数十亿年期间，它们会逐渐分道扬镳。
明日的图片: pixels in space
