Sirius Tau system

This is a list of places featured in Douglas Adams's science fiction series, The Hitchhiker's Guide to the Galaxy. The series is set in a fictionalized version of the Milky Way galaxy and thus, while most locations are pure invention, many are based on "real world" settings such as Alpha Centauri, Barnard's Star and various versions of the Earth.

"The Galaxy" is our home galaxy, the Milky Way, though it is referred to exclusively as "the Galaxy" in the series. Apart from a very brief moment during the first radio series, when the main characters were transported outside the galactic plane into a battle with Haggunenons, and a moment when one of Arthur's careless remarks is sent inadvertently through a wormhole into "a distant galaxy", the Galaxy provides the setting for the entire series. It is home to thousands of sentient races, some of whom have achieved interstellar capability, creating a vast network of trade, military and political links. To the technologically advanced inhabitants of the Galaxy, a small, insignificant world such as Earth is considered invariably primitive and backward. The Galaxy appears, at least nominally, to be a single state, with a unified government "run" by an appointed President. Its immensely powerful and monumentally callous civil service is run out of the Megabrantis Cluster, mainly by the Vogons.

A "former Galactic Empire" is mentioned in several adaptations of the series. By the time set in the Hitchhiker's series, the government of the Galaxy is referred to as the "Imperial Galactic Government", though it is further explained that the term 'Imperial' is now something of an anachronism. In the television adaptation of the series, the name Imperatala Galacticon is used in one graphic as an alternate name for the previous Galactic Empire.

...
Wikipedia