A&A Supplement series, Vol 121, March 1997, 451-454
Received April 16; accepted June 11, 1996
'M.D. Guarnieri
, and G. Carraro
Send offprint request: G. Carraro
Department of Mathematical Physics, Torino University,
Torino, Italy
Torino Astronomical Observatory, Strada Osservatorio 20, I-10025 Pino
Torinese, Torino, Italy
Department of Astronomy, Padova University, vicolo
dell'Osservatorio 5, I-35122 Padova, Italy
A colour magnitude diagram (CMD) extending to 
mag is given for 444
stars in the region of the galactic cluster Berkeley 66. The V and I
photometry of a nearby field is also reported. This
object appears very faint, highly contaminated by foreground stars and very
reddened. The apparent distance modulus (m-M) and the colour excess
are guessed to be 17.5 and 1.1, respectively, with an uncertainty
of at least 30%. Adopting these values the comparison of the CMD
with theoretical isochrones from
the Padova group provides an age around 1.0 Gyr.
keywords: open clusters: Berkeley 66 -- HR diagram