| Abstract: | A study of transformation equations for photoelectric photometry was carried out,based on the observations of Johnson standard stars in Praesepe using the 60cm reflector equipped with the DC photoelectric photometer at Beijing Astronomical Observatory,Chinese Academy of Sciences. The transformation equations were applied to the reduction to the UBV photometry for three variable stars. The light curves we derived and their standard errors were compaired with the results from the differential observation. |
