Starbase 9

Starbase 9 was a facility active in the 23rd century. It was located in the Zendi system and is near Sol, Vulcan, Pyris VII in the general vicinity of Gamma Persei.

USS was en route to Starbase 9 when it nearly collided with a black hole and was sent back in time to 1969. 

Other references

 * Comtet, Nicole. "Home Sweet Home." (Orion Press)
 * Doyle, Diane. "Gorgon's Lair." (Orion Press)