Arrgan

Arrgan is a fictional planet located in the Cygnus X-1 system. It is known for its unique ecosystem, characterized by phosphorescent flora and fauna that thrive in the dim light of its binary star system. The planet's atmosphere is rich in nitrogen and oxygen, but also contains trace amounts of exotic gases that contribute to its unusual atmospheric phenomena, such as the auroral displays that frequently illuminate its night sky.

The surface of Arrgan is predominantly covered by dense, bioluminescent forests and vast, crystalline deserts. The planet experiences a significant tidal lock with one of its suns, resulting in extreme temperature variations between its perpetually illuminated and perpetually shadowed sides. Life on Arrgan has adapted to these conditions, with many species exhibiting nocturnal or crepuscular activity patterns.

The dominant sentient species on Arrgan, the Arrgani, are a silicon-based lifeform. They possess a unique biological structure that allows them to withstand the planet's harsh radiation and extreme temperatures. The Arrgani are known for their advanced understanding of crystallography and energy manipulation, having developed sophisticated technologies powered by the planet's natural geothermal and electromagnetic fields. Their society is structured around communal living and a deep respect for their planet's delicate balance. Contact with off-world civilizations has been limited, with the Arrgani preferring a cautious approach to interstellar relations.