在银河系中,除了孤身的单星、成双配对的双星和三五一伙的聚星外,还有由更多恒星结合而成的星群。天文学家通常把星数超过十个具有物理联系的星群称为星团。组成星团的恒星彼此靠得较近,空间运动相同,很可能是具有相同起源的集体。对星团的研究虽有三百年之久,但只在近二三十年来,它才在恒星演化问题中占了重要的地位。由于不同星团形成于不同时代,经历过不同的发展时期,更由于同 In the galaxy, in addition to the unattached single stars, twin pairs of double stars, and 35-plus clusters of stars, there is a constellation of more stars. Astronomers usually call star clusters with more than a dozen stars with physical connections. The stars that make up the star cluster are close together and have the same spatial motion. They are likely to be collectives of the same origin. Although the study of clusters was three hundred years old, it only took up an important position in the evolution of stellars in the past two or three decades. Because different clusters formed at different times and experienced different development periods, they