Starbase 26 was a Federation starbase that was operated by Starfleet in the 23rd century. Starbase 26 is located in the star system of a blue star, in the general vicinity of Pyris and a black hole. (ST reference: Star Trek Maps)
In 2266, the USS Enterprise stopped off at the starbase to receive replacement security personnel. Among those boarding at this time were "Jon Anderson", Luis Benitez, and Leslie Parrish. (TOS - Errand of Vengeance novel: The Edge of the Sword)