Invernia II

Invaria II is a planet located in the Alpha Quadrant or Beta Quadrant. During an ion storm on the planet, a young girl died because there was no one with medical knowledge there to save her. Julian Bashir was on the planet at the time; he sometimes told himself that this incident was why he began a medical career. 

Judging by the planet's name, it is likely located in the Invaria system.