Dynamically constrained, assumed circular orbit of a single arm driver. For a 1.9 M☉ central star, the best-fit ±1σ orbit has a radius of ﹩1\buildrel{\prime\prime}\over{.} {07}_{-0\buildrel{\prime\prime}\over{.} 09}^{+0\buildrel{\prime\prime}\over{.} 11}﹩ (﹩{172}_{-14}^{+18}﹩ au).