SDXL version (improved superstructure detail) now available here: https://civitai.com/models/151497?modelVersionId=169398
Trained on 25 high quality images of various types of Dyson spheres. The main concept is a star surrounded by a superstructure of some sort. This is fairly experimental, just to test out the concept. I might split this out into sphere style, ring style, etc.
I'd recommend starting with a weight of around 0.6-0.8, and aiming lower if you plan to combine it with other LoRAs.