Expected values, Ṗ_B,exp (black), for the directly measured time derivative of the orbital period in the two scenarios where the PSR J1910−5959A binary is a field object (panel a) or is associated with NGC 6752 (panel b). The horizontal scales in panel a and b respectively are the pulsar distance, D, in kpc, and its depth inside the cluster, r_∥, in units of r_⊥. The red line indicates the value Ṗ_B,obs measured from our timing. In panel a the vertical green line indicates the distance of NGC 6752 from the Sun. In panel b the vertical dot-dashed blue lines delimit the range for r_∥ where Ṗ_B,exp is consistent to Ṗ_B,obs. In both panels, dashed lines delimit the 1σ limits for the plotted quantities.