Tyrellian system

Tyrellian Sector
Political Powers United Federation of Planets Klingon Empire Romulan Republic Romulan Star Empire Notable Individuals Tyrellian Commonwealth Federation and Starfleet Klingon Empire Romulan Star Empire Romulan Republic All Others Planetary Systems Federation Territory Tyrellian system Klingon Empire Territory Romulan Republic Territory Romulan Star Empire Territory Starfleet Presence USS Gorkon Tyrellian Defence and Exploration Taskforce Edit this nav

The Tyrellian system is a binary star system in the Tyrellian Sector, located in the Beta Quadrant. It is home to the Tyrellian species and a member of the United Federation of Planets. Located close to the Federation-Klingon border, and the Romulan Neutral Zone, it has become a diplomatic and trade hub between the three political powers.

Stars

---

Palan in transit across Denak A and B.

Denak A and B form a detached binary (i.e. there is no mass transfer between them) in close orbit around a common barycenter.

Name	Classification	Mass (M☉)	Temperature (K)	Age (Gyr)
Denak A	G (Yellow)	1.22	6210	4.4
Denak B	G (Yellow)	0.72	5390	4.4

Planets and Moons

---

Overview

Diagram of the Tyrellian system, with habitable moons shown. (Not to scale)

• Planets: 11, in P-type (circumbinary) orbits
  • Habitable planets: 1, Tyrellia. It is the 5th planet, the original homeworld of the Tyrellians, and currently habitable only through artificial means.
  • Habitable moons: Palanon, Ereina and Senya, all in orbit of Palan, the 6th planet, a large blue gas giant.

Capital World

Yarista, the capital city of Palanon.

• Name: Palanon
• Population: ≈ 3.4 billion

The vast majority of the Tyrellian population do not live on their homeworld, but rather the largest of the habitable moons in the system, having migrated there after their homeworld was rendered uninhabitable by a natural disaster.

The world is an exemplification of the attitude "aim for peace, but prepare for war" that pervades modern Tyrellian culture. The whole system is well-protected by an array of early warning systems, as well as a standing fleet of Starfleet vessels. Palanon itself boasts an array of planetary defence systems that are among the most potent in the Federation. Despite this, the desire to live peacefully with their neighbours is in clear evidence. The capital city, Yarista, hosts numerous embassies, including major diplomatic missions from the Romulan Star Empire, the Klingon Empire, and the Ferengi Alliance, amongst others. Visitors are welcomed, and the population is diverse.

Other major cities on Palanon include Cotral.

Colonised "Ark" Moon

• Name: Ereina
• Population: ≈ 350,000

The interior of one of Ereina's forest biodomes.

Ereina is an "ark world", colonised by the Tyrellians with a view to preserving as much life from their home planet as possible. Much of the moon's surface and seas are enclosed within biodomes simulating the conditions of Tyrellia's original biomes. Access is restricted to scientific and educational visits only -- with the occasional tour for diplomats -- and the planet's inhabitants primarily consist of scientists, facility staff, and their families.

Homeworld

• Name: Tyrellia
• Population: ≈ 250,000

Tyrellia, the barren homeworld.

The homeworld of the Tyrellians is unique within the Federation, known for being only one of three inhabited planets to lack a magnetic pole, and one of only seven without any kind of atmosphere. This unusual situation is due to the as yet unexplained loss of the planet's geomagnetic field, which ultimately resulted in total atmospheric ablation by the solar winds of the binary stars.

While their homeworld grew more hostile to life, the Tyrellians created deep underground shelters, preparing to migrate their population to the first of Palan's habitable moons, Palanon, while the flora and fauna were to be moved to another habitable moon, Ereina. It is in these shelters that the current population live, protected from the intense solar radiation that bombards the planet's surface. A substantial part of this small population is an array of scientists dedicated to finding an answer to why the planet lost its geomagnetic field, and how it could be reestablished. Also present in large numbers are archeologists and engineers, dedicated to preserving the structures -- both underground and overground -- for the day when the Tyrellians can return home.

Additionally, Starfleet has taken advantage of the planet's unique circumstances to establish a large space observatory complex.