Oan (planet)

Oani
Oani is the name of both a planet visited by Enterprise in the 2150's and the race of humanoids living there. The planet consists largely of water, with numerous islands where the Oani people lived. The whole race was killed by a creature made of energy, which called itself "Wanderer," although it was initially thought that the cause of death was a microbe or a form of radiation. (ENT novel: Surak's Soul)