Standardisation of broad band photometry of equatorial standards.

The published photometry of the fainter equatorial standards for broad band photometry is not homogeneous. The U-B systems differ from one another. V from Crawford et al. (1971) and B-V from Moffett and Barnes (1979) and from Landolt (1983) need colour corrections to reduce them to the Johnson system. The R and I photometry is in three different systems and there are zero point errors present. The present note is mainly concerned with B and V. The external s.e. of V and B-V are ±0^m.004 or ±0^m.005 for the better series.