The Tycho system was an inhabited planetary system. A planet in this system, Tycho IV, was the homeworld of the dikironium cloud creature. This system was over a thousand light years from Argus X.
In 2257, the Federation starship USS Farragut visited this system. Eleven years later, the USS Enterprise pursued the dikironium cloud creature into this system. (TOS: "Obsession")
In 2371, the location of the Tycho system was labeled in the star chart Data and Picard were studying in stellar cartography on the USS Enterprise-D. (Star Trek Generations, okudagram)