Beta Cassius system
From Memory Alpha, the free Star Trek reference.
The Beta Cassius system was an inhabited star system in Federation space. One of the passages into the system was by a stargate. By the mid-24th century, Haven, a planet of this system, had by treaty become a protectorate of the Federation.
In 2364, two ships visited the system: the USS Enterprise-D for shore leave, and a Tarellian starship attempting, successfully, to contact Wyatt Miller. (TNG: "Haven")
