Absolute proper motion of the Galactic open cluster M 67

We derived the absolute proper motion (PM) of the old, solar-metallicity Galactic open cluster M 67 using observations collected with CFHT (1997) and with LBT (2007). About 50 galaxies with relatively sharp nuclei allow us to determine the absolute PM of the cluster. We find ( cos δ, )J2000.0 = (-9.6 ± 1.1, -3.7 ± 0.8) mas yr-1. By adopting a line-of-sight velocity of 33.78 ± 0.18 km s-1, and assuming a distance of 815 ± 50 pc, we explore the influence of the Galactic potential, with and without the bar and/or spiral arms, on the galactic orbit of the cluster.