SCYON Abstract

Received on February 25 2005

Berkeley 22, an old and distant open cluster towards the Galactic anticentre

AuthorsLuca Di Fabrizio (1), Angela Bragaglia (2), Monica Tosi (2), Gianni Marconi (3,4)
Affiliation1 INAF-TNG,
2 INAF-Oss. Astron. Bologna,
3 INAF-Oss. Astron. Roma,
Accepted byMonthly Notices of the Royal Astronomical Society ,
Links Berkeley 22


We present deep CCD BVI photometry of the distant, old open cluster Berkeley 22, covering from the red giants branch (RGB) to about 6 magnitudes below the main sequence (MS) turn-off. Using the synthetic Colour - Magnitude Diagram method with three different types of stellar evolutionary tracks, we estimate values and theoretical uncertainty of distance modulus mod0, reddening E(B-V), age tau and approximate metallicity. The best fit to the data is obtained for 13.8 <= m-Mo <= 14.1, 0.64 <= E(B-V) <= 0.65, 2 <= tau <= 2.5 Gyr (depending on the amount of overshooting from convective regions adopted in the stellar models) and solar metallicity.