Iota Geminorum is a Class G9, fourth-magnitude star in the constellation Gemini. It is called by the proper name Propus, meaning "forefoot" in Arabic. Iota Geminorum is a variable star located about 325 light-years from Earth. It forms an unequal pair with 59 Geminorum (app. mag. 5.77; Class F4III), which is more or less the same distance away.

In Star Trek, Iota Geminorum IV is the fourth planet in the Iota Geminorum star system and the homeworld of the tribble. Reptiles are the natural predators of tribbles on this world, and are known to keep the tribble population in check, which when removed to other environments breed uncontrollably. (ENT: "The Breach")

In order to fulfill their self-given task to hunt the tribble species to extinction, the Klingons presumably bombed Iota Geminorum IV in the late 23rd century, which suggests it might now be a part of the Klingon Empire. (DS9: "Trials and Tribble-ations")