Sirius

Sirius, also known as the Dog Star, was one of two stars in a binary system located in the Mutter's Spiral galaxy.

Astronomical data
Sirius was roughly 8.6 light years away from Sol. (AUDIO: Max Warp) It was a binary star system, with two white stars. (TV: The Curse of the Black Spot) It had at least five planets: Sirius Alpha, (AUDIO: Max Warp), Androzani Major and Minor, (TV: The Caves of Androzani), Sirius IV (TV: Frontier in Space) and Sirius 5. (TV: City of Death)

History
Sirius was used as a guide-point for navigation on Earth for much of its early history. It was only later found to consist of two stars. In the 17th century, Sirius was still used for navigation in sailing. When Captain Henry Avery obtained a spaceship, one of his trips was to see Sirius. (TV: The Curse of the Black Spot)

There was apparently an art gallery on Sirius 5 that Romana thought could rival The Louvre. (TV: City of Death)

By the time of the Earth Empire, the Sirius system had been colonised by humans, though by 2540 Sirius IV was an independent dominion planet. (TV: Frontier in Space)

The Sirius Conglomerate was a major power in the system, involved in activities on the planet Androzani Major, which held reserves of spectrox, a substance conferring longevity. (TV: The Caves of Androzani)