From Halopedia, the Halo wiki
Yonhe is considered a small moon.
Yonhe was the homeworld of the Yonhet species.
Discovery by the Covenant
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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