Based on the shape seen in the bitmap http://coastal.lic.wisc.edu/wisconsin-ims/wisconsin-ims.jpg found at http://coastal.lic.wisc.edu/wisconsin-ims/wisconsin-ims.htm (the web site of the University of Wisconsin Sea Grant Institute). And on my hand-coded star shape.
Stars of the State of Wisconsin free icon was designed by AdamStanislav for icons Png and presented to its users.
AdamStanislav
12/5/2017