How large will the quilt be and how big is the panel? I would make the size of the star dependent on the center size.
Here are two great 5 Point Star which are paperpieced. One is, as written, 8" but could be smaller or larger ( you could go to a copy center and do that) or it could be made larger by placing a border around it. The other actually appears to be a short tutorial on how to do it with another PP pattern. Looking at your picture, you could try a white star on the blue background with a red (or red and white stripped) border.
http://www.quilterscache.com/F/FiveP...StarBlock.html
http://alittlebitbiased.blogspot.com...-tutorial.html