Omicron system
The Omicron system was an inhabited planetary system located in the Omicron sector of the Beta Quadrant. Its fourth planet, Omicron IV, was inhabited by a native species. (TNG: "Manhunt"; TOS: "Assignment: Earth")
Crewmembers aboard Federation starships used the system as a reliable point when computing distances between astronomical locations. Lieutenant Commander Data often told an "amusing" anecdote concerning how he computed the distance between the Omicron system and the Crab Nebula "by using the square root of pi and multiplying it by nine to the third power,". In 2365, he recounted the story to Jean-Luc Picard and Lwaxana Troi, much to their boredom. (TNG: "Manhunt")