CCD UBVRI photometry of 7 open star clusters

We derive cluster parameters and mass functions from new UBVRI CCD photometric observations of ~3500 stars reaching down to V~20mag for the distant southern open star clusters...针对遥远南天疏散星团，本研究通过对约3500颗恒星开展极限星等可达V波段20星等的全新UBVRI波段电荷耦合器件（Charge-Coupled Device，CCD）测光观测，从中推导出星团参数与质量函数。