Just a simple scene of asteroid belt around a star I know it's not realistic, but this is the best I could do.

Particle system is used for creating asteroid belt, I have also used a torus (it's hidden so you must unhide it to see it in viewport) with collision to stop the particles from scattering everywhere and finally I mimicked [this tutorial](http://elbrujodelatribu.blogspot.com.es/2013/07/blender-cycles-procedural-stars-world.html) for creating the star field.

I hope someone finds it useful.