Oh, that's different. What you're seeing on the website is simply a long exposure as the stars move across the sky. And in the case of the example photo they are looking directly at the north star/polaris which gives it the rotational look.
This is not something I'm going to do in Tenkoku. You might be able to do this yourself though, I imagine it would involve using Blit() to render the screen to a texture over the course of many frames, using an custom shader that compares the pixels with each blit and only adds the brighter ones to the buffer.
