A graphic of the Lima Sierra system.
The Lima Sierra system is a star system, with four planets, visited by the USS Enterprise-D in 2365. The third planet in the system has an extremely unusual orbit that defies conventional mechanics. (TNG: "Loud as a Whisper")
The Lima Sierra system also appeared in the starchart Data and Picard were studying in Stellar Cartography in 2371. (Star Trek: Generations)