History and specifics
The Sigma system was located in the vicinity of the planet Zeron II. According to Spock in the 2260s decade, the system was totally barren. In the year 2266, the Federation starship USS Enterprise was on its way through the Sigma system when it made a pass by Zeron II. (TOS comic: "Dark Traveler")
- While Spock claimed the system was barren, by the 24th century a planet called Sigma V was home to a contacted civilization. It is possible that planet was in a different "Sigma system" and the names are similar, however it is also possible that the presence of non-aligned planetary life was missed or simply wasn't notable in Spock's description.
- Sigma primary star