Sirius VII

The Soers' reality transmuter was made on Sirius VII. Charlie Smith read this detail off an etching in the device itself, cluing him in to the Soers' ignorance on the complexities its operation. (AUDIO: The Soers' Ditch)

Behind the scenes
Sirius VII belongs to the Sirius system, first mentioned in TV: The Caves of Androzani, which also includes Androzani Major and Minor.