Memory Alpha
Memory Alpha

Pentarus III was the third planet of the Pentarus star system. The planet had two moons, including the "barely M-class" Lambda Paz (Pentarus IIIB). (TNG: "Final Mission")

"pen-TAR-us" was the pronunciation for Pentarus from the script pronunciation guide. [1]
In the Star Trek: Star Charts ("United Federation of Planets I"), Pentarus III was listed as a Federation member in 2378.