1. Make a circle with the right color and size and reduce the hardness to zero and just click away a dozen times or so until the "starshine" looks right.

2. Go to Filter>Render>Lens Flare

Simple as that.

Sp5(V) r g b hexsun-photoshop.jpg
O 155 176 255 #9bb0ff
B 170 191 255 #aabfff
A 202 215 255 #cad7ff
F 248 247 255 #f8f7ff
G 255 244 234 #fff4ea
K 255 210 161 #ffd2a1
M 255 204 111 #ffcc6f