The 23 SiO masers examined in this study, overlaid on an HST F153M image. The green square represents IRS 9, which is found to exhibit a velocity larger than the maximum escape velocity at its radius (i.e., it is locally unbound from the GC). The green arrow shows the direction of its HST proper motion (not to scale). The yellow squares correspond to three masers proposed to be locally unbound (SiO-16, SiO-21, and SiO-25), but the new HST proper motions indicate that they do not exceed their maximum escape velocities. The red circles show the positions of the other masers in the sample. All sources have projected distances of R ≤ 45″ (∼1.8 pc) from SgrA* (cyan cross).