That's my center.
My size was a guess. For what looks like a 12 inch square, I started with 2.5 inch strips of 3 fabrics, after they were sewn together I cut on the 45 degree angle, and sewed those triangles together to form the 90 degree angles.
I went to the free paper pieced pattern that was posted in the spring discussion, here it is if anyone's interested:
http://www.quilterscache.com/S/Spinn...heelBlock.html
I'll try that for the border of smaller stars... either that or get lazy and just do pinwheels. :D