This is a quick and dirty render showing the aura effect you can make by using volume radials in back of an infinite plane assigned to a glass material and rotated 90 degrees. The radial on the left is grouped with a larger sphere assigned with a fire mat, but with the right material and a little experimenting you can get sun-spots and flare-like effects. I wish I could find the pic I did of a binary system. I even had an acretion disk going where the two stars were swapping solar material. Good luck. Dan