Today, I added a backdrop with stars. I took a lazy route here: I added a plane and use the same technique as for the smoke: just a particle emitter with super low speed, long living ico spheres. I did throw some collor randomization into the material to mimic red, orange and blue stars.
The volumetric part is just not going to work, I don’t have any time for it, but I like the way it turns out even without it.
Here is a render with quality close to he final output:

The animation is now rendering, so I hope to publish the final result tomorrow.
If I understand correctly, I have to put the final results in the gallery and refer to this thread, right? Or do I need to mention my entry for this challenge somewhere else as well?