Trekipedia

Sectors

Quadrants were divided into numbered Subquadrants and Sector Zones. The intersection of a subquadrant and a sector zone resulted in a roughly cube-shaped Sector Grid, which was 5000 light years long and 3600 light years high along the galactic plane; the width varied by distance from the galactic core—at the rim, it could be as wide as 8727 light years. Each sector grid was then divided into a cubic grid of 100 Sector Quads, which were then further broken down into 900 ore more roughly cubical Sector Blocks, each measuring nearly 100 cubic light years (varying by distance from the galactic core). Finally, sector blocks were divided into 100 sectors, each measuring 20 cubic light years. Typically, a sector contained approximately 40 stars, about two-thirds of which were part of binary, trinary, or even quadrinary systems. However, in dense globular star clusters, a sector may have contained several thousand stars, and in the void between spiral arms, sectors may have contained no stars at all.^[2]

Sector numbers were a nine-digit sequence with the first two digits representing the sector grid, the first digit of which represented the subquadrant and the second the sector zone (e.g. Sector Grid 15 was the intersection of subquadrant 1 and sector zone 5); the next two digits represented the sector quad; the next three digits represented the sector block; and the final two digits represented the sector proper. Since the vast majority of explored sectors were contained in the sector grids bordering the Federation, the sector grid designation was often omitted. In common usage, it was not unusual to refer to a sector by its last five digits, or even simply its last two digits. The last five digits would be unique for a distance of 800 light years in any direction, and the last two digits would be unique for a distance of 80 light years. Prior to the mid-24th century, sector quads were commonly, though erroneously, referred to as “quadrants.” This practice fell into disuse, however, due to the widespread confusion it often generated.^[2]

By convention, the Sol Sector was known as Sector 001;^[1] this designation had no relation to the overall numbering system, but instead indicated that this was the first sector explored by Human space vessels. Nearby sectors were similarly numbered in the order in which they were explored, beginning with the Alpha Centauri Sector, Sector 002.^[2] Other sectors thus numbered included:

• Sector 003: Terra Nova Sector^[2]
• Sector 004: Sigma Draconis Sector^[2]
• Sector 005: Vulcan Sector^[2]
• Sector 006: Andorian Sector^[2]
• Sector 007: Tellar Sector^[2]
• Sector 008: Ophiucus Sector^[2]

References

• ^[1]TNG-175: The Best of Both Worlds, Part II
• ^[2]STSC: Star Trek: Star Charts