Sample low-eccentricity orbits that are consistent with our astrometry. Each orbit shown is within 1σ of the best fit solution. The side panels show the size of the residuals to each of these fits. All residuals are consistent with zero to within our uncertainties. For all four planets, our best fit reduced χ² is less than 1, suggesting that our uncertainties are slightly overestimated. This is likely due to our conservative approach to uncertainty assignment for both the positions of the planets and the positions of the central star.