For the Klingon warships, please see IKS Bortas.
Bortas was a location in the Beta Quadrant.
In 2257, its location was labeled on the star chart showing the trajectory of Lieutenant Spock's shuttle. (DIS: "An Obol for Charon")
This location was only mentioned in writing.
According to the Stellar Cartography: The Starfleet Reference Library ("Stellar Cartography", pp. 31; "Federation Historical Highlights, 2161-2385"), Bortas was a star in Klingon space. This was the location of a historic battle.