Vectna

Vectna is the fifth planet of the Kas system, a binary star system composed of a white subgiant star and a distant-orbiting companion red dwarf star. The system has a total of 12 planets, including one Neptunian gas giant, as well as two distinct asteroid belt regions. It is administered as the hub world of the Kas Federacy, an autonomous alien protectorate to which the other worlds of the Kas system are subject. The population of the Federacy is around 290 billion goliaths, roughly 2.5% of the total goliath population. It is the only autonomous political entity assigned to that species.
Vectna itself is an arid terrestrial world and the homeworld of the goliath race. Its dense, breathable atmosphere is composed mostly of 70.3% xenon, 25.7% oxygen, 3% argon, and trace other gases. It is classified as a Sonoran Garden world, with 48% ocean cover and light glaciation in the south pole. Its strong geomagnetic field and dense, insulating atmosphere protects it against the worst of its two stars' powerful radiation, generated by the interaction of its liquid outer core and solid mantle. Its composition is rich in magnesium, iron, and oxygen, with most of the iron being part of its solid inner and liquid outer core. Its surface is largely silicates and magnesium compounds, with significant deposits of iron, gold, and rare earth metals. Despite its mass, it is only about 17% more dense than Earth, leading to a fairly comfortable surface gravity of 1.42 g. Its atmospheric density and pressure are moderately higher than a convention Garden-world nitrogen-oxygen atmosphere, largely due to the high presence of xenon and argon gases, but it is breathable and has proved amenable to the evolution of complex life.
A combination of its distance from its main star and its almost 42° axial tilt leads to stark differences in weather conditions and long climatic seasons, developing temporary ice caps that last for one to three Earth years in its southern hemisphere. Its long, hot seasons compelled the evolution of complex life resistant to heat and aridity, resulting in flora roughly similar to Earth acacias, shrubs, legumes, and succulents. A great diversity in fauna evolved, initially in its stormy seas some 3 billion years ago. Extinction events and climate shifts caused by heavy volcanism and numerous impact events abounded throughout its geological history, the most recent being some 100 million years ago. Fauna bearing a morphological similarity to Earth diapsid reptiles evolved and became the dominant form of complex life. Around 2 million years ago, the progenitors of the goliaths, Bufopugnator habilis, evolved as migratory, tool-using creatures. They developed an erect stance and, around half a million years ago, achieved anatomical modernity.
The goliaths eventually came to settle across Vectna, develop a rich and complex series of cultures and civilizations, and invented agriculture, metallurgy, industry, and space technology. In 1881, a global thermonuclear war devastated Vectna's ecology and killed 80% of the goliath population. It took almost a thousand years to recover, during which the majority of the goliaths spread outward to colonize other worlds to form the Scutum Union. Those remaining on Vectna lived hardscrabble lives of violence and scarcity, attempting to rebuild civilization on their own as the world was largely depopulated and the goliath interstellar empire quarantined Vectna and gave it little assistance. Before the 21st century, the homeworld experienced a population deficit as radiation poisoning, disease, drought, and famine caused widespread death, malnutrition, and stillbirths. It slowly began to grow after that point, but it has yet to recover to its pre-war levels. This recovery has been complicated by the Reclamation War, an attempt by civil authorities to regain control of the planet.