Thorsten Renk:

Thorsten Renk:
Add a 4th layer to the sun (next to disc, inner halo and outer halo). While the inner/outer halos change with atmosphere conditions, the new layer is supposed to represent the effect of blinding brilliance - ideally it adds a suitable ray structure to the sun. The effect is most prominent in space (where I'm most keen on seeing it admittedly) because there all atmospheric halo effects are absent and we end with a really unrealistic white disc.

Some screenshots and discussion there

http://forum.flightgear.org/viewtopic.php?f=47&t=27216