BVRI observations of 235 bright quasars

Photometric observations of 235 extragalactic objects that are potential targets for the Space Interferometry Mission (SIM) are presented. Mean B, V, R, I magnitudes at the 5%...本数据集提供了235个河外天体的测光观测数据，这些天体均为空间干涉测量任务（Space Interferometry Mission，SIM）的潜在观测目标，并给出了5%条件下的平均B、V、R、I星等。