Alpha Omicron asteroid belt

From Memory Alpha, the free Star Trek reference

The Alpha Omicron asteroid belt is an asteroid belt located in the Alpha Omicron system which was uncharted until until Stardate 44614.

The asteroids in the system contain large quantities of meklinite and traces of kefnium. The kefnium is a source of food for a spaceborne species which the entity dubbed Junior is a member of. Several adult members of the species lived in the asteroid belt. (TNG: "Galaxy's Child")