Open AccessBerkeley 22, an old and distant open cluster towards the Galactic anticentre
Author(s) -
Di Fabrizio L.,
Bragaglia A.,
Tosi M.,
Marconi G.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.08963.x
Subject(s) - physics , metallicity , distance modulus , open cluster , photometry (optics) , astrophysics , red giant branch , globular cluster , hertzsprung–russell diagram , astronomy , star cluster , cluster (spacecraft) , red clump , stellar evolution , stars , computer science , programming language
We present deep CCD BVI photometry of the distant, old open cluster Berkeley 22, covering from the red giant branch (RGB) to about six 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 uncertainties of the distance modulus ( m − M ) 0 , reddening E ( B − V ), age τ and approximate metallicity. The best fit to the data is obtained for 13.8 ≤ ( m − M ) 0 ≤ 14.1, 0.64 ≤ E ( B − V ) ≤ 0.65, 2.0 ≤τ≤ 2.5 Gyr (depending on the amount of overshooting from convective regions adopted in the stellar models) and solar metallicity.