The main races at the Kentucky Derby may be about the horses, but the women are there to compete in fashion — namely those legendarily extravagant hats. This year, actress Zoe Saldana wore a one-of-a-kind chapeau designed by noted American milliner Eric Javits on behalf of Derby sponsor GREY GOOSE Vodka. But not just interested in the fashionable side of the day, Zoe autographed the hat to be auctioned off to benefit benefit the St. Jude Children’s Hospital and an additional donation being made to the Barnstabe Brown Foundation. You can bid on Zoe’s signed hat at the online auction site Clothes Off Our Back. The auction, which started May 5 runs through May 15th so don’t wait to put in your bid!