VI photometry in NGC 188

We used HST-WFPC2 to study the white dwarf luminosity function of the old open cluster NGC 188 in order to determine a lower limit to the age of the cluster (~5Gyr) by looking...本研究借助哈勃空间望远镜-广域行星相机2（HST-WFPC2），对年老疏散星团NGC 188的白矮星光度函数展开观测研究，旨在通过观测……确定该星团的年龄下限（约50亿年）。