Development of a three channel photometer for UPSO, Naini Tal

The design and performance of a portable three channel photometer installed at the Uttar Pradesh State Observatory (UPSO), NainiTal is described. The photometer is modular and the whole unit can be disassembled as individual channels such that the system can also be used as a single channel or two c hannel photometer. The system also has provision to monitor a guide star. T he instrument was put into operation since November 1999 on the 1m Sampurna nand telescope at UPSO, Naini Tal. Since then, it is used extensively for t he 'Survey of rapidly oscillating Ap (roAp) stars in the northern sky' from UPSO. Observational results using this new photometer in its initial phase of operation are discussed. The advantage of having continuous sky measure ment is demonstrated.