I am suspecting you guild wants you do try your hand at drafting a pattern given the 10" size. A mariners compass can easily be drafted to make a 10" finished block but you need to know how to do it. But it is by no means a fast and easy block. I don't find them overly difficult but to draft, then make your PP templates does take some time.
Here are 10" star blocks I found on Quilters Cache. This is just a sampling if you go there and search you will find others.
http://www.quilterscache.com/K/KnightStarBlock.html
http://www.quilterscache.com/N/NewStarBlock.html
http://www.quilterscache.com/M/MalteseStarBlock.html
http://www.quilterscache.com/M/MichelesStarBlock.html
http://www.quilterscache.com/L/Light...tarsBlock.html