The Tycho system was an uninhabited 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 the Argus planetary system.
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")
The Tycho system appeared in the starchart Data and Picard were studying in stellar cartography in 2371. (Star Trek Generations, display graphic)