Effects on the evolution of orbital elements (top panel) and the deviation from GR (bottom panel). Each case is integrated independently. The cases are (i) full MOG (solid blue line), (ii) fifth-force contribution alone (solid red line), iii) space-time contribution alone (solid yellow line), and (iv) GR (dashed black line). Cases (ii) and (iii) are not physical in MOG, but are used for diagnostic purposes, as explained in Sect. 5.3. An explanation of the labels can be found in Table 1. For each orbital element µ^a, the definitions of ∆ µ^a and δµ^a are given in Eqs. (34) and (36), respectively.