Position residuals of Sgr A* relative to J1745−283 and J1748−291 relative to J1745−283 toward the easterly (top) and northerly (bottom) directions. The J1748−291 positions are offset for clarity. Error bars are ±1 σ and include estimates of systematic effects. The position uncertainties are greater for J1748−291, owing partly to its weakness and its larger angular offset from J1745−283, compared to Sgr A*. The dashed lines are the variance‐weighted best‐fit proper motions. The position of J1748−291 relative to J1745−283 is constant within 2 σ formal uncertainties and consistent with that expected for two extragalactic sources.