Céltérian

Céltérian is a fictional planet in the Andromeda Galaxy, featured in the "Chronicles of Xylos" science fiction series. It is known for its unique bioluminescent flora and fauna, which illuminate the planet's surface during its long twilight periods. The dominant intelligent species on Céltérian are the Aerions, a humanoid race with translucent skin and large, dark eyes, adapted to the planet's low light conditions.

The planet's atmosphere is rich in a rare gas that, when interacting with specific plant spores, causes the widespread bioluminescence. Céltérian's geography is characterized by vast, crystalline forests and deep, echoing caverns. The Aerions have developed a sophisticated society based on telepathic communication and a deep reverence for their planet's natural cycles. They are known for their advanced understanding of bio-engineering, utilizing the planet's natural resources to create intricate living structures and tools.

The "Chronicles of Xylos" series often depicts Céltérian as a place of both wonder and danger, where visitors must navigate the alien ecosystem and the complex social structures of the Aerions. The planet serves as a central hub for intergalactic trade and diplomacy in the series, though its inhabitants generally prefer to maintain a degree of isolation, protecting their unique environment. Encounters between off-worlders and the Aerions are often central to plot developments, exploring themes of cultural exchange and ecological preservation.