Yall-Ull (Gliese 667)

A triple-star system in the Inner Sphere

Gliese 667 - Another view
The three stars of this system as seen from the surface of the supermundane shell surrounding Malkas

Yall-Ull (Gliese 667) System - A Triple Star System in the Inner Sphere -Data Panel

SystemSystem Name: Gliese 667 (GJ 667), HD 156384, HIP 84709, HR 6426, Yall-Ull
Components: 3
1) Yelsal (Gliese 667 A)
2) Tehno (Gliese 667 B)
3) Arcas (Gliese 667 C)
- Distance from Guniibuu: 5.244 ly (J2000)
- Distance from Sol: 23.873 ly (J2000)
- Constellation: Scorpius
YelsalName: Yelsal, Gliese 667 A
Physical characteristics:
- Mass: 1.452E+30 kg (0.73 x Sol)
- Radius: 528,732 km (0.76 x Sol)
- Luminosity: 0.254 x Sol (bolometric)
- Temperature: 4,700 Kelvin
- Spectral type: K3V
- Age: 8 billion years
System: The two main dwarf planets that orbited around this star at 0.11 and 0.27 AU were restored to pristine conditions after the rise of the restorationist mindset in the system. Others were either taken apart for the construction of swarms of habitats and infrastructures that encircle this star, or rearranged into massive habitat complexes housing up to hundreds of billions of sophonts.
TehnoName: Tehno, Gliese 667 B
Physical characteristics:
- Mass: 1.372E+30 kg (0.69 x Sol)
- Radius: 486,990 km (0.70 x Sol)
- Luminosity: 0.181 x Sol (bolometric)
- Temperature: 4,500 Kelvin
- Spectral type: K5V
- Age: 8 billion years
System: Kbem, the most massive dwarf planet, orbiting this star at 0.30 AU, is the only major object in the Yall-Ull system that is completely covered in an ecumenopolis.

Yelsal-Tehno binary orbit Orbital characteristics:
- Average separation: 13.115 AU
- Period: 39.86 years
- Eccentricity: 0.58
Gl 667 C planets
Image from Dangerous Safety, amended by Steve Bowers
The planetary system of Gliese 667 C; L'daso, Horvat and Malkas (before the construction of the suprashell around Malkas)

Planets of Gliese 667 C - The Arcas System

ArcasName: Arcas, Gliese 667 C
Physical characteristics:
- Mass: 6.562E+29 kg (0.33 x Sol)
- Radius: 222,624 km (0.32 x Sol)
- Luminosity: 0.017 x Sol (bolometric)
- Temperature: 3,700 Kelvin
- Spectral type: M1.5V
- Rotation period: 105 days
- Age: 8 billion years
Planets1) L'daso (Gliese 667 C b): Acidi-Neptunian Cere-Jotunnian
Semi-major axis = 0.049 AU
Orbital period = 7.200 days,
Eccentricity = 0.13,
Mass = 7.5 x Earth,
Radius = 2.479 x Earth
2) Horvat (Gliese 667 C c): Hydro-Neptunian Cere-Jotunnian
Semi-major axis = 0.121 AU,
Orbital period = 28.16 days,
Eccentricity = 0.03,
Mass = 5.4 x Earth,
Radius = 1.938 x Earth
3) Malkas (Gliese 667 C d): Tholi-Neptunian Cere-Jotunnian
Semi-major axis = 0.265 AU,
Orbital period = 91.40 days,
Eccentricity = 0.08,
Mass = 6.3 x Earth,
Radius = 2.381 x Earth
This planet is now covered by a habitable suprashell.

Inner Yall-Ull - Arcas binary orbit
Orbital characteristics:
- Average separation: 220 AU
- Period: 2,467 standard years


The triple system of Gliese 667 was observed to hold three planets orbiting the more distant component, Gl 667 . An unmanned interstellar probe was launched in 505 AT to explore this system. By the time the probe reached the system two centuries later SolSys was in the nadir of a Dark Age, and the data sent back by the probe was never received.

The system was colonized by the First Federation in 1109 AT. The colony mission was fronted by Clan Yall, a close ally of House Genen. However the planets in this system, L'daso, Malkas and Horvat were not suitable for terraformation, so Clan Yall and their Genen collaborators concentrated on building a wide range of novel and experimental environments inside space habitats in orbit around and between these worlds.

Clan Yall's expertise in ecosystem building was instrumental in the creation of Neo-helix in the neighboring system; a fact they feel is often ignored when comparing the accomplishments of House Genen families.

The transition between the end of the First Federation and the rise of the megacorporations was a particularly difficult one for this system. Clan Yall experienced extensive in-fighting, that often spilt over into proxy wars involving client populations throughout Gliese 667. Waves of sectarian radicalization occurred, with anti-transapient and pro-anthropist sentiment becoming entrenched. The entire system became a backwater of sorts for the next millennium.

Gliese 667 returned to the galactic stage in 3901 when it was the chosen neutral site for a conference to negotiate an end to the Conver Wars. While this conference failed to meet the lofty goals set out for it, this initial conference did set the groundwork for the Ian Treaty of 3932. Both the Ambi Limis and the Geminga Orthodoxy remembered this humanitarian effort on behalf of their citizens and retained close ties to the system.

By the Age of Crisis most of the larger habitats had been set aside as nature reserves, and the population had shifted to exclusively living in bubblehabs floating in the atmospheres of these worlds. Numerous coalitions arose at this time, the largest being the colorfully-named Confederation of the Million Floating Eyots.

The Malkas suprashell
Image from Steve Bowers
The Malkas Suprashell is 17838 km in radius, and supports an Earthlike environment on the surface.

The Malkas Suprashell

In 8077 AT, the Arcas system clan-council began to construct a supramundane shell surrounding the planet Malkas. This structure was completed in 9609. With a radius of 2.8 x Earth, this shell has an surface gravity of 0.81 gees. The shell only covers two thirds of the planet, and is bounded at north and south by a tall atmosphere wall. This shell rotates to give a diurnal period of 25 hours.

A significant proportion of the population of the Malkas suprashell are polymorphic in form, switching between different bodyplans at will. A large continent on the northern edge of the suprashell is set aside as a reserve for lazurogened Neanderthals, who are developing their own distinctive culture in this region.

Gliese 667
The sky above the Malkas suprashell, another view
The current population of the Yall-Ull system is cosmopolitan in composition. Of note, the system supports populations of Grays, and Raffins. Together the Raffins and Grays have built a relatively small ecumenopolis, or city world, on the surface of the minor planet Kbem in the Tehno system.

Kbem Ecumenopolis
Image from Steve Bowers
The Kbem ecumenopolis
Related Articles
Appears in Topics
Development Notes
Text by Mark Ryherd,
updated by The Astronomer, Dangerous Safety, and Steve Bowers 2020
Initially published on 21 May 2012.