Mu Arae

Mu Arae was a star in Sector Z-6, in the Milky Way Galaxy's Beta Quadrant. The system's sole inhabited planet,, joined the United Federation of Planets in 2380. 

History
In the 2370s, the Federation starship USS da Vinci transplaned the Koan homeworld from its original system into an orbit around Mu Arae. 

Alternate timeline
In an alternate timeline where Vulcans had remained a violent and emotional species, Mu Arae was close to the border between the Interstellar Union and the Klingon Empire. In 2293, the Interstellar Guard starship IUES returned from a reconnaissance mission in Klingon space. The Kumari was ordered to a position three parsecs from Mu Arae, remaining within one light-year of the border.