Tri-Betaline (or T-B) was a star system located in or near Federation space, somewhere in the galaxy's Alpha or Beta Quadrants. The system contained a number of worlds, including the thirteenth planet, Syntagus Theluv, which was home to a humanoid species known as the Theluvians. In 2364, the USS Enterprise-D entered the system on a mission to survey the system and establish contact with the Theluvians. Prior to that date, no Federation starship had ever traveled to the sector Tri-Betaline was located in. (TNG comic: "... Where No One Has Gone Before!")