Cut and pasted for your reference.
Sarhesen is the homeworld of the kett, located in an unknown system of the Andromeda galaxy. It is the capital of the Kett Empire and seat of its Senate. According to kett history, Sarhesen was united by the invention of exaltation.
I stand corrected. None of the data I read mentioned the homeworld as in the Andromeda system itself. However, I would like to reserve my opinion simply as its a wiki and anyone can edit it. If someone could point toward where in the game the info is, I would happily check it myself.
I think you learn about the kett empire more during the side quests "Know Your Enemy and Dissension in the Ranks" There is comms recordings between the kett as you progress iirc.
