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4. The color-magnitude diagrams

In Fig. 8 (click here) we show the V vs. V-I CMDs for fields 5139D-F. For each field the photometry is based on a single pair of "long" V & I exposures. The CMD's based on "short" exposures are presented in Fig. 9 (click here). The frames used for construction of CMD's shown if Figs. 8 (click here) and 9 (click here) are listed in Table 7 (click here). The presented CMDs were cleaned from stars of relatively poor photometry. In case of data plotted in Fig. 8 (click here) we removed 17%, 23% and 13% of stars with V<18 for fields 5139D, 5139E and 5139F, respectively.

  table391
Table 7: List of frames used for construction of CMDs shown in Figs. 8 and 9

The presented CMDs show the same features which have been already noted in Paper I. Several likely hot subdwarfs with 18.2<V<19.5 and tex2html_wrap_inline1581 can be noted. Also a numerous candidates for blue stragglers are visible, especially in fields 5139D and 5139E. The apparent main sequence of field stars can be traced from the base of the subgiant branch of the cluster up to tex2html_wrap_inline1583 which is the bright limiting magnitude of our photometry. This sequence is probably related to the so called "old disc" discussed recently by Jonch-Sorensen & Knude (1994) and Ng et al. (1995).

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.

  figure406
Figure 8: The CMDs for fields 5139D (left), 5139E (center) and 5139F (right)

  figure411
Figure 9: The CMDs for fields 5139D (left), 5139E (center) and 5139F (right) based on shortly exposed frames


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