Centaurus IX is a planet, located in the Alpha Centauri system. During the Dominion War, the planet was held by the Dominion. In 2374, Admiral William Ross was planning a Starfleet ground assault on Centaurus IX and was to present his plan to his fellow Admirals Sitak and Coburn. Ross later decided against the ground assault, preferring to give Benjamin Sisko the meeting with Starfleet Command to outline his plan to retake Deep Space 9. (DS9 - The Dominion War novelization: ...Sacrifice of Angels)