Sector 875 was a region of space, a sector located somewhere in the galaxy's Alpha or Beta Quadrants, a location on star charts used by the Federation in the 23rd century.
History[]
In 2269, the rogue planet DT-262 passed through the territory of an unnamed humanoid species native to Sector 875. Emanations from the planet proved deadly to that species' biological and mechanical processes, so they dispatched a spacecraft to investigate. When its commander discovered the Federation starship USS Enterprise near the planet, he assumed it was responsible for the deadly planet, and he destroyed the Enterprise using temporal phase weapons.
However, the calamity was prevented because James T. Kirk became unstuck in time during the attack, and he was able to divert the rogue planet before it could harm the sector's inhabitants. (TOS - New Visions comic: "Time Out of Joint")