C-111 system

The arrival roster at Deep Space 9 listing the C-111 system

C-111 system was the official designation for a planetary system in the Alpha Quadrant. This system consisted of a primary and at least three planets. The third planet, Beta III, was the homeworld of the Beta III natives, a pre-warp capable species. (TOS: "The Return of the Archons", ENT: "In a Mirror, Darkly, Part II")

The Archon was the first vessel to explore the system in the 2160s; the ship was destroyed by the Landru entity on the third planet. In 2267, the USS Enterprise conducted a followup mission, investigating the loss of the Archon. (TOS: "The Return of the Archons")

In 2370, the USS G'Mat traveled from the C-111 system to Deep Space 9. (DS9: "Whispers")

There were other planets that were named Beta (number): Beta V, Beta VI, and Beta XII-A. It was never stated in canon what systems these planets were located in, so one or more of them might have been in this system.

File:Star-chart alpha-beta quadrant.jpg

The location of the Tholian Assembly and Romulus on "The Explored Galaxy" wall chart

"The Explored Galaxy" was a map of charted space in the Alpha Quadrant. The area of space between the Tholian Assembly and Romulus represented the extent of exploration by the Federation in the late 23rd century. Both locations were identified in DS9: "The Search, Part II", "Call to Arms" as being located in this quadrant. The chart, first seen chronologically in Star Trek VI: The Undiscovered Country, was also seen in several Star Trek: The Next Generation and Star Trek: Deep Space Nine episodes set in the 24th century, from the year 2364 to 2370. These were TNG: "Conspiracy", "The Measure Of A Man", "The Emissary", "The Mind's Eye", "The Game", and DS9: "In the Hands of the Prophets", "Cardassians".