Sci-Fi Pulsar

Hello all,
this is my latest render. It took me more time than I first intended, but I am satisfied with the result. The image shows an planet/star inspired by a pulsar with a sci-fi-ish color mix. I hope that you like the result.

I am open for critique so please tell me what I can do better. I am still new to rendering because I focused on hard surface modeling before.Thanks.

Source of background image: NASA

Technical Info:
Blender 2.76b on Ubuntu 14.04LTS
Cycles Render
3000 samples per pixel

Here some other pictures of the scene:

Compositing (I am a bit confused too):

Tell me if you like it. :slight_smile: