A small unregarded yellow sun.
—Sol's description[src]

Sol was an "unregarded yellow sun" residing in what was considered the unfashionable end of the Western Spiral Arm of the Galaxy. It was considered small compared to other suns and stars in the Universe. It was at the centre of the solar system which contained the planet Rupert and the supercomputer Earth, before the latter was destroyed. Venus, Neptune and Pluto are briefly mentioned as being part of this solar system orbiting Sol, as well as asteroids.

It was mentioned in The Hitchhiker's Guide to the Galaxy and features in the opening of a number of Hitchhiker's media, including the imagery of Sol rising on the last day of the Earth in the television series.

Solar system

Sol and the planets orbiting it were known as the solar system.

These planets included:

The supercomputer Earth also orbited Sol for 10 million years (between Venus and Mars) before its destruction by the Vogons.