pixel size 24 μm. The scale was 0 .36 pixel −1 giving 12 .6 on a side. The CCD gain was 10 e −/ADU while the read out noise was 5.3 e −. To improve the S/N ratio, the observations were made in 2 ×2 pixel binning mode. The observational information alongwith dates are listed in Table 2 . Identification maps of the observed regions of the clusters are shown in Fig 1 .