The Atoan system, a star system situated within the Ghost Nebula in the Expansion Region, encompassed Atoa, the Atoan homeworld, alongside several other inhabited planets.
Not long after the Galactic Empire's establishment, the system became the site of a significant Imperial military operation. Darth Vader, accompanied by the 501st Legion, was dispatched to probe the vanishing of Admiral Garoche Tarkin. The truth was that he had switched his allegiance to Lady Saro, the High Priestess of Atoa and a co-leader of the system. Ultimately, both Saro and Tarkin met their demise at the hands of Vader.