Title: A proposal for enhancing technosignature search toward the Galactic center

Abstract: We discuss the possibility of enhancing intelligent life searches toward the Galactic center. From the clockwork orbital motions of stars around the Sgr A${}^*$ black hole, we can determine the distance to the Galactic center at an exceptional accuracy, despite its remoteness $\sim 8.3$kpc. In addition, we can define precise reference epochs by selecting a prominent object such as the bright B-type star S2. These properties have a particular affinity for the coordinated signaling scheme which was hypothesized by Seto (2019) for systematically connecting intentional senders to searchers without a prior communication. If S2 is actually being used as a common reference clock, we can compress the search directions around the Galactic center by more than two orders of magnitude, with the scanning interval of $\sim16$yr.