Investigation of serendipitious WFC sources

The serendipitious WFC sources under investigation, i.e., those which just happened to lie in the field of view while another object was being studied, were disappointing. The integration times were chosen to suit the primary target not the serendipitous targets. UX UMa, CZ Ori, BI Ori, WX Cet and AR And were not detected. A long (approximately 17 ksec) pointed observation of UX Uma (PI Wood) has since been carried out (February 1993) and the data is expected shortly. The other observations were much more successful. V471 Tau was observed with the WFC for 6.5 hrs with the S1 filter and 1.1 hrs with the S2b filter. It was easily detected with a count rate of 0.03 cps in the S1 filter and 0.15 cps in the S2b filter. The oscillations were seen, even before the data was folded, as was expected from preliminary results from the survey (Barstow et al. 1992). The pointed observations provide a much better phase coverage of the oscillations than did the survey data where the coverage was sparse. These data will be presented in a paper with the PSPC data (PI's Robinson and Shipman) and the pulse profiles in the different wavelengths will be compared.