Median magnitude and position angle (measured from north to east) and 1σ confidence range for pulsar timing models with increasing numbers of Fourier components. The Fourier modes have frequencies of ﹩N/{T}_{\mathrm{obs}}﹩, with T_obs ∼ 10 yr. The two-component timing solution produces a poor fit and a discrepant proper motion measurement, while models with four or more Fourier components simply absorb statistical fluctuations and decrease the measurement precision. With the 10-component model, the proper motion is unconstrained, as there is strong degeneracy between the Fourier component with frequency ∼1 yr and the pulsar position. Values of the magnitude for two and 10 components are above the upper figure boundary.