Fantoma was the fourth planet in the Valivarre star system.
It was a ringed gas giant that was slightly smaller in size than Jupiter in the Sol System.
Behind the Scenes
In the novels and comic books of Robotech II: The Sentinels, Fantona is described as a large, terrestrial planet: not a gas giant. In this version, the Zentraedi had originally been engineered as giants so that they could survive the gravitaional pull of the massive planet while mining its surface for monopole ore--a metal necessary for the construction of starship hulls. When the Zentraedi returned to the Robotech Masters' homeworld with the REF as micronians, they were later returned to full-size in order to resume their mining duties.