SIMBAD references

UV (195 nm) and Stroemgren uvby photometry of a 110 square degree field at high southern galactic latitudes are analyzed through a comparison of i) UV magnitudes for 57 stars of various types common to the published TD1 catalogue and the Very Wide Field Camera (VWFC); and ii) observed and theoretical two-colour diagrams. The higher sensitivity of the VWFC (≃0.5magnitude) and its more complete survey are exemplified by the detection and UV measurement of a series of objects with moderate UV-excess in addition to detection of some very blue objects of various nature down to fainter than 12th magnitude in the optical domain. A deeper survey with a VWFC-type instrument could provide a complete sample for studies of the group properties of faint blue stars. During the uvby reductions it was found that the usual procedure of plotting residuals as functions of declination, hour angle and airmass can be a powerful and diagnostic test of photometer rigidity.