Make a Shining Sun & Rays in Adobe Illustrator
Note: I'm using Illustrator CS3 on Windows, if you have a different version there may be slight differences in the way of doing steps. Also you should be familiar with some basic Illustrator functions & tools.
1st draw a perfect circle with the Ellipse Tool while holding the Shift key.
Now, keeping the circle selected, select the Scale Tool, put it in the center of the circle, & while holding Alt key make a left mouse click, a box will pop-up, set the Scale on 120% & click the Copy button (not OK)
You have now a bigger circle in front of your first one, bring the 2nd behind the first from the Layers Palette or from the Object menu: Object > Arrange
Now, keeping the bigger circle selected, go to the Filter menu: Filter > Distort > Zig Zag...
In the box, check the Preview check box, set the Ridges per segment to 8, & for the Size value, it depends on the size of your circle, start moving the slide bar & looking to your circle changing, half of its anchor points will be moving towards the center & the other half away from it, when you see that the distance between the center & the interior points is about half the distance between them & the outside points, hit OK to save changes & close the box.
That done, go select the Direct Selection Tool & will select all the outside anchor points (which means interior points will remain unselected), to do so, hold the Shift key while clicking on the points.
Once done, select the Scale Tool, go to the center of your distorted circle, hit Alt & make a click, a window will pop-up, check the Preview box & enter a value for scale, 500% or 600% would make it I think.
OK, we are almost done, for sky, add a big rectangle behind your sun, fill it with a gradient that goes from yellow to blue, & choose Radial as type of gradient (all that in the Gradient Palette), of course make sure the yellow is in the center of the rectangle, doesn't matter for now if it's in the center of your sun or not.
Now, fill the distorted circle with a similar gradient, the blue tone should be exactly the same & the yellow clearer than in the rectangle.
Fill the small non distorted circle with a solid color which is the yellow tone you used for the distorted gradient.
OK, now let's synchronize the gradients of the sky & the sun rays (the distorted circle); to do so select both shapes using the Selection Tool (black arrow) & holding Shift. Now select he Gradient Tool, you should be able to see a point marking the center of the sky rectangle & another point marking the center of the rays, put your cursor over this one & drag till you reach the border of the rays or a little bit before then release.