Norellus was an inhabited planet inside the Delphic Expanse.
In September of 2153, Enterprise visited a deuterium station there while searching for the Xindi. While on Norellus, Captain Jonathan Archer met B'Rat Ud, a V'radian chemist who promised to sell Archer the formula for synthesizing trellium-D if they met at B'Rat's shop on the Xanthan homeworld. (ENT: "Rajiin")
This planet was only mentioned in dialogue.