A ternary star system in the Gamma Quadrant, some 70,000 light years from Bajor, which lies closest to the far mouth of the Bajoran wormhole.
Idran is the first place in the Gamma Quadrant ever reached through the wormhole. In Emissary, Sisko and Dax take the runabout Rio Grande into the Denorios Belt and emerge at the other end of the passage, where Dax identifies the nearby system from the record of a probe that surveyed the area in the 22nd century.
She describes Idran as a ternary system with no Class M planets, about five light years from the wormhole's mouth. Its position shows that the runabout has travelled roughly 70,000 light years in moments, which makes the wormhole the first stable one known.
The system gives the Gamma terminus its usual point of reference, and ships entering Dominion territory through the wormhole in later seasons arrive in its neighbourhood.