The dependence of number density, mass density, and average mass per star as a function of the logarithm of the distance from the centre r_c. From top to bottom: a) the number density D of stars in the cluster obtained with a binning of 2 pc in steps of 1 pc. Outside 10 pc the bin size is increased to get a better signal-to-noise ratio. The error bars are Poisson errors; b) the observed mass density ρ (black dots) using the same binning and a density distribution (red crosses) from a Plummer model (Eq. (4) with M_t = 276   m_⊙ and r_co = 3.10 pc); c) the average mass per star obtained as ρ/D. Its decrease from the centre outbound characterises the mass segregation in the Hyades, at present time.