UBV(RI)c photometry of equatorial standard stars. A direct comparison between the northern and southern systems.

UBV(RI)c photometry of 212 stars from Landolt's list of equatorial standards is presented. The observations are tied to the system defined by Cousin's E-region standards. A comparison of the present results with Landolt's reveals reasonably good agreement for (V-R)c and (V-I)c, but marked systematic differences for (B-V) and (U-B). The UBV systems of Cousins and Landolt are evidently not the same and both probably differ from Johnson's original system.