StarGen is a Geometry Nodes system for generating 360-degree starfields and volumetric nebulae. The setup allows for non-destructive creation, with all parameters accessible directly from the modifier tab, eliminating the need to interact with the node editor. Users can easily adjust star size, color, brightness, distribution, and density to suit their scenes. The tool includes five nebula shader presets configured for the Cycles render engine and supports animated twinkling star effects. Because it functions as a continuous 360-degree environment, the generated space scenes seamlessly surround the camera from any angle.