Five old open clusters more in the outer Galactic disk
  New photometric material is presented for 6 outer disk supposedly old, Galact
ic star clusters: Berkeley 76, Haffner 4, Ruprecht 10, Haffner 7, Haffner 11,
and Haffner 15, that are projected against the rich and complex Canis Major
overde nsity at $225^o \leq l \leq 248^o $, $-7^o \leq b \leq -2^o$. This CCD
data-set, in the UBVI pass-bands, is used to derive their fundamental
parameters, in particular age and distance. Four of the program clusters turn
out to be older than 1 Gyr. This fact makes them ideal targets for future
spectroscopic campaigns aiming at deriving their metal abundances. This, in
turn, contributes to increase the number of well-studied outer disk o ld open
clusters. Only Haffner 15, previously considered an old cluster, is found to be
a young, significantly reddened cluster, member of the Perseus arm in the third
Galactic quadrant.
  As for Haffner~4, we suggest an age of about half a Gyr. The most interesting
result we found is that Berkeley~76 is probably located at more than 17 kpc
from the Galactic center, and therefore is among the most peripherical old open
clusters so far detected. Besides, for Ruprecht~10 and Haffner~7, which were
never studied before, we pr opose ages larger than 1 Gyr. All the old clusters
of this sample are scarcely populated and show evidence o f tidal interaction
with the Milky Way, and are therefore most probably in advanced st ages of
dynamical dissolution.
