SIMBAD references

We report BVRI photometry of stars in 12 selected extreme ultraviolet ROSAT fields with the goal of obtaining firm identifications of the optical counterparts to the ROSAT sources. We present BVRI magnitudes and finder charts for 10 optical counterparts identified previously in a spectroscopic survey. Among the 10 sources are 7 probable white dwarfs, 2 dwarf Ke stars, and one cataclysmic variable. One of the white dwarf sources (RE J2207+252) appears to reside in a visual binary system with a K4V companion. Two sources (RE J1853+503 and RE J2117+484) have yet to be identified with visible stars, although our photometry suggests some candidates for future spectroscopic investigation.