The velocity dispersion profile of NGC 1851, derived considering the 184 members with radial velocity accuracy better than 1.2 km s^-1. Data have been binned in groups of 20 each, moving by 5 from one group to the next. The dotted and solid lines give the 66 and 90 percent confidence regions for the dispersion. The central velocity dispersion as reported in Harris (1996) is also shown (diamond). The vertical line marks the radius where the internal acceleration of gravity is a₀ (assuming M/L = 1). Overplotted on the data is a Gaussian plus a constant (not a fit to the data) to highlight the flattening of the VDP that occurs well within the cluster tidal radius of 41 pc (Harris 1996).