The Paxan homeworld was the sole planet orbiting a T-Tauri type star in a pocket of the Ngame Nebula. Unusually for such a star system, it fell within Class M range, and was capable of sustaining life. According to the Paxans, it was in fact a protoplanet which they had terraformed in order to better conceal their whereabouts.
Ironically, the unusual nature of the planet prompted the USS Enterprise-D to investigate it in 2367. The Paxans had set up a trap involving a wormhole near the planet in order to goad visiting ships into a scenario where they would move away without investigating, but their unfamiliarity with positronic brains, and the presence of Commander Data on board, thwarted their plan. However, once the situation became clear, the two parties cooperated to fix the situation, and Starfleet did not learn of the significance of the planet. (TNG: "Clues")