Multi slit spectroscopy at the Telescopio Nazionale Galileo was employed to measure radial velocities for 20 stars in the direction of the old open cluster Berkeley 29 , the farthest known in our Galaxy .
Membership information was derived for stars along all the red giant branch , in particular near its tip , and on the red clump .
The sample of bona-fide cluster members was used to revise the cluster distance to \sim 15 kpc , on the basis of an empirical comparison with the red clump in open clusters with known distances .
A metallicity [ Fe/H ] = -0.74 \pm 0.18 was also estimated using the colours of spectroscopically confirmed red giant stars .