New Harmony
From Halopedia, the Halo wiki
New Harmony was a UNSC colony world. It may or may not have been related to Harmony, another UNSC colony.
Sometime before 2537, the Battle of New Harmony took place on the colony. During the battle, a prowler, the UNSC Razor's Edge, managed to attach a telemetry probe to a retreating Covenant Frigate, allowing it to track the ship and locate K7-49.[1]
It is the homeworld of both Kat-320 and Jun-266.[2]