Keeneland will add 10 horses--colts by Authentic, Constitution, Into Mischief, Maclean's Music and Uncle Mo, along with fillies by Authentic, Curlin, Gun Runner and Not This Time--to Book 1 of its September Yearling Sale scheduled for Sept. 9-10, the auction house said in a release on Thursday. Opening day of the sale will include these five supplements: Hip 177, Limelight (Authentic), a colt from the family of MGISW National Treasure (Quality Road). Consigned by Bridie Harrison, agent for Peter E. Blum Thoroughbreds; Hip 178, filly by Curlin who is the...