UBVI photometry of the intermediate age open cluster NGC 6939

We present CCD UBVI photometry of the nearby, intermediate age open cluster NGC 6939. Using the synthetic Colour - Magnitude Diagrams technique we estimate the following parameters: age between 1.3 and 1.0 Gyr (depending on whether or not overshooting is considered), reddening 0.34<E(B-V)<0.38 and distance modulus 11.3<mod_0<11.4 .