2 Observations

The BVR photoelectric photometric observations of the six RS CVn stars were carried out during the period November, 1995 to February, 1997, using the 0.35 m Schmidt-Cassegrain telescope (C-14) equipped with SSP-5A photoelectric photometer and Johnson standard broad band filters. The detector used in SSP-5A photometer is R4457 photomultiplier tube (PMT). The response curves of the B and V filters and R4457 PMT detector system closely match those of Johnson standard B and V response functions, respectively, whereas our R passband is close to the $R_{\rm c}$ in the Cousins system. For each variable star, a star as close as possible to the program star, having colour and magnitude similar to the program star, and used by previous observers were chosen as comparison stars. The details of variable and comparison stars are given in Table 1. Observations were corrected for the atmospheric extinction and transformed into the standard photometric system. Each data point is an average of four to five independent observations. The uncertainty in $\Delta V$, $\Delta(B-V)$ and $\Delta(V-R)$ are 0.012, 0.015 and 0.013 mag, respectively.