CCD photometry of distant open clusters. I. Berkeley 22, Berkeley 29 and Berkeley 54.

We present deep BVI photometry for three previously unstudied rich and distant open clusters. The color-magnitude diagrams of all studied objects show well-defined main-sequences and clumps of helium burning giants. Estimates of age, reddening and distance are given for all target clusters. Ages of Be 54 and Be 29 are close to the age of M 67 (about 4Gyr on the scale of Geneva isochrones). Age of Be 22 is about 3Gyr. Heliocentric distance of Be 29 is estimated at 10.5 kpc while its galactocentric distance is about 19kpc. Be 29 seems to be the most distant galactic open cluster known in sense of its heliocentric as well as galactocentric distance. A clearly marked sequence of binaries is visible on the color-magnitude diagram of Be 29. Two likely candidates for evolved giants belonging to the very extended halo of Be 29 were identified. Our photometry suggests extremely low metallicity of Be 29. Several candidates for variable stars were found in the field of Be 54.