From Halopedia, the Halo wiki
Yonhe is a small moon located in the Orion Arm, formerly within the dominion of the Covenant Empire. The moon is the homeworld of the Yonhet. When Yonhe was discovered by the Covenant, the Yonhet's small native population was viewed as militarily insignificant, with there being little value in considering them as full signatories to the Covenant Empire. Instead, Yonhe and the Yonhet were incorporated into the Covenant fringe.
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