The Sun (Sol)
A small unregarded yellow sun situated in the uncharted backwaters of the unfashionable end of the Western Spiral Arm, orbited at ninety-two million miles by Earth.
Stellar Dossier: The Sun (Sol)
"Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun.
Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea."
— The Hitchhiker's Guide to the Galaxy, Introduction
The Sun, designated in imperial stellar atlases as Sol (and occasionally dismissed by Megadodo researchers under astronomical catalogue entry ZZ9 Plural Z Alpha / Prime), is an ordinary main-sequence yellow dwarf star burning hydrogen via thermonuclear fusion at roughly fifteen million Kelvin in its core.
The "Unregarded" Status
In the grand galactic scheme, Sol is considered almost aggressively mediocre:
- Stellar Output: It is neither large enough to end its life in a spectacular supernova nor small enough to boast the exotic gravitational quirks favored by luxury stellar cruises.
- Galactic Position: Positioned approximately twenty-six thousand light-years from the vibrant galactic core, situated in the quiet Orion-Cygnus spur of the Western Spiral Arm.
- Commercial Value: Aside from providing modest solar photons to dry laundry on Sol III, the system possesses virtually no strategic antimatter deposits, luxury spa gas giants, or fine dining establishments.
The Sol Planetary System
Sol is orbited by four inner terrestrial worlds, four outer gas and ice giants, and an untidy cloud of frozen cometary debris:
- Sol I (Mercury): Scorched, airless iron rock, unsuitable for hitchhiking due to lack of shade.
- Sol II (Venus): Runaway greenhouse catastrophe; atmospheric pressure capable of flattening a Vogon heavy hauler like an empty beer can.
- Sol III (Earth): Home of humanity, dolphins, mice, and tea-seeking travelers. Cataloged in the Guide as "Mostly harmless".
- Sol IV (Mars): Rusty desert world; historically populated by paranoid radio telescopes from Sol III looking for non-existent canal systems.
- Outer Gas Giants (Jupiter, Saturn, Uranus, Neptune): Swirling ammonia and methane atmospheres, popular among zero-gravity thrill seekers.
Astrogation, Light-Speed Benchmarks & Hyperspatial Bypass Hazard
In The Hitchhiker's Guide to the Galaxy's discussion of the mindboggling size of space, Sol serves as the baseline benchmark for interstellar distances:
- Sol to Earth: Traveling at the speed of light ($186,000$ miles a second), light takes eight minutes to travel from the star Sol to the place where the Earth used to be.
- Sol to Alpha Proxima (Alpha Centauri): It takes four years more for light to arrive at Sol's nearest stellar neighbour, Alpha Proxima.
- Sol to Damogran: To reach the other side of the Galaxy—for instance, Damogran—takes light five hundred thousand years (though the hitchhiking record for this distance is just under five years, during which you don't get to see much on the way).
Due to bureaucratic initiatives rubber-stamped on Alpha Centauri, Sol currently sits directly in the projected transit corridor of Hyperspatial Express Route 42. Ships traveling through the Sol system are advised to keep emergency sub-etha transmitters online, keep towels within arm's reach, and check local planning notices before parking in orbit.
Sirius Tau
The primary star of the Sirius Tau system, infamous throughout the known Galaxy because the Complaints Division of the Sirius Cybernetics Corporation covers every major landmass of its first three inner planets.
Soulianis and Rahm (The Twin Suns of Magrathea)
The fabled binary red sun system located deep within the impenetrable dust clouds of the Horsehead Nebula, orbiting and illuminating the legendary custom-planet factory world of Magrathea.