Error ellipses in the R- plane for stars in the anticentre. The ellipses have been drawn for 60 stars from the AC20-ϖ∕σ_ϖ > 3 sample chosen randomly but with weight of expR in order to sample better the different R. The ellipses are coloured by magnitude G and the error bars are included as black lines. The error ellipses are oriented pointing towards the R₀ -(v_c,⊙ + V_⊙) point (blackstar).