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TTA HomeCelestia / Arcturus (Alpha Bootis)


Arcturus is the common name of Alpha Bootis, a K2III red giant star 41 light-years from Sol.  Arcturus is 22 times as large as Earth's sun, but only 1.5 times as massive.

There are ten planets (twelve, if you count the worldlings).  As a red giant, Arcturus has a larger habitable zone than smaller stars like Sol, extending from roughly 7 AU out to 22 AU from the center of the system.  There are two inhabitable planets and at least one possible candidate for terraforming within this distance.  The sixth planet, Aether, is the destination of the Voyager mission, and upon arrival will be the site of mankind's first extra-solar colony.  In the distant past, all of the planets inhabitable in the Arcturian system were frozen and lifeless, but the star's expansion has warmed them considerably.

The colonization team, in an effort to inspire a sense of cultural identity among the population, held a population-wide drawing to choose the name of each of the major substellar bodies in the new system.  As such, they are a diverse group of names with no common theme.

Wight (Arcturus I)

An airless body that orbits close to the primary.  It has been burnished by the heat of Arcturus' flare up and has one of the highest known albedos of a natural object.

Tavly (Arcturus II)

This planet is an inferno, wracked by geological activity and runaway volcanism, with a thick, poisonous atmosphere.  Lava seas can easily be made out from space.

Satyr (Arcturus III)

A high-gravity venusian hothouse.

Ozymandias (Arcturus IV)

A striking world with an unusual marbled appearance.  The terrain consists of vast sandy deserts and extensive fissures, chasms, and canyons snaking across the surface.  Ozymandias has a breathable atmosphere, but not much in the way of natural resources, and Aether is a much more suitable planet, but in the future Ozymandias may also be colonized.

Aether (Arcturus V)

This planet is the site of the Arcturus project, mankind's first globally organized, extrasolar colony, and destination of the first several vessels in the Voyager and Connestoga series of bulk transports.  Aether is rather similar to Earth.


First and smallest of three gas giants in the Arcturus system.  It is a brown-white world a little larger than Uranus and more than twice as massive.  It has four named moons: Hactar, Gort, Kent, and Pipsqueak.

The Worldlings

The worldlings are planetary bodies that precede and follow Talos at the planet's trojan points.  Worldling A is mars-like and supports a thin atmosphere, so it may make a good candidate for terraforming in the future.


The second Arcturian gas giant, a violet, ringed planet around the size of Jupiter, but over 30% more massive.  The planet has five named moons: Heritage, Dancer, Dream, Poxy, and Cyclopes. Cyclopes possesses an (unbreathable) atmosphere.


The most imposing planet in the Arcturian system is this black-and-red gas giant.  It is nearly eight times as massive as Jupiter, and 1.6 times as large (theorized to exceed maximum Jovian size due to internal heating of unknown cause).  Overlord has nine named moons: Radix, Underling, Shadow, Macbeth, Demesne, Andreas, Rex, Tesla, and Ahmed's Jilt. Of these, Tesla is the most intriguing, due to the strong electrical discharges that occur constantly in its atmosphere.  It is unknown whether this is an effect of radiation from Overlord or if Tesla itself generates the power somehow, but it far exceeds the worst thunderstorms on Earth in both duration and ferocity.


A rocky and airless world.


A tiny body on an eccentric orbit far on the outskirts of the system.  Someone has planted a sign at the north pole that reads "Last rest area for 41 LY"