A theory is derived relating the configuration of the cores of active
galaxies, specifically candidates for presumed super-massive black hole
binaries (SMBHBs), to time-dependent changes in images of those galaxies. Three
deflection quantities, resulting from the monopole term, mass quadrupole term,
and spin dipole term of the core, are examined. The resulting observational
technique is applied to the galaxy 3C66B. This technique is found to under
idealized circumstances surpass the technique proposed by Jenet et al. in
accuracy for constraining the mass of SMBHB candidates, but is exceeded in
accuracy and precision by Jenet's technique under currently-understood likely
conditions. The technique can also under favorable circumstances produce
results measurable by currently-available astronomical interferometry such as
very-long baseline-interferometry (VLBI).Comment: 15 pages, 2 figures, accepted in General Relativity & Gravitatio