4. The color-magnitude diagrams

As a by product of our survey we obtained V vs. V-I CMD's for all 5 monitored fields. In Fig. 8 (click here) we show the CMD's for fields 104A and 104E. For each field the final photometry was obtained by merging measurements extracted from "long" and "short" exposures. Photometry obtained for fields 104A-B extends to brighter magnitudes than photometry obtained for fields 104C-E. The frames used for construction of CMD's of monitored fields are listed in Table 8 (click here). Any detailed analysis of these data is beyond the scope of this paper. We note only that our data can be used to select candidates for cluster blue stragglers.

  

Frame Field Filter FWHM

s arcsec

mr5228 104A 420 V 1.1

mr5176 104A 120 V 1.2

mr8181 104A 60 V 1.05

mr5382 104A 400 I 1.2

mr5381 104A 120 I 1.25

mr8182 104A 10 I 1.35

mr5227 104B 420 V 1.0

mr5177 104B 120 V 1.4

mr8184 104B 60 V 1.0

mr5385 104B 400 I 1.3

mr5386 104B 120 I 1.45

mr8183 104B 10 V 1.0

mr7889 104C 500 V 1.0

mr7902 104C 50 V 1.0

mr7903 104C 500 I 1.0

mr7904 104C 50 I 1.05

mr14597 104D 420 V 1.05

mr14589 104D 61 V 1.05

mr14592 104D 420 I 1.20

mr14591 104D 60 I 1.15

mr14595 104E 420 V 1.1

mr14596 104E 60 V 1.0

mr14593 104E 420 I 1.1

mr14594 104E 60 I 1.1

Table 8: List of frames used for construction of CMD's for fields 104A-E

  
Figure 8: The CMDs for fields 104A (left) and 104E (right)

All photometry presented in this section was submitted in tabular form to the editors of A&A and is available in electronic form to all interested readers (see Appendix A). The potential users of this photometry should be aware about possibility of some systematic errors of the photometry. These errors are most likely to be significant for relatively faint stars. The CCD chip used for observations by the OGLE suffers from some nonlinearity. More details on this subject can be found in Paper I.