星团

Hubble was able to resolve six variable stars in M31.

哈勃望远镜能辨梅西叶星云星31的六颗变星。

We also describe the basic principle of white dwarf cosmochronology and its application in defining the age of the Galactic disk, globular clusters, open clusters and Galactic halo.

介绍了白矮星宇宙纪年学研究的基本原理及其在银盘、球星、疏散星以及银晕年龄确定方面的应用现。