12929 Periboea, provisional designation: 1999 TZ1, is a dark Jupiter trojan from the Trojan camp, approximately 54 kilometers (34 miles) in diameter. It was discovered on 2 October 1999, by American astronomer Charles W. Juels at the Fountain Hills Observatory in Arizona. Originally considered a centaur, this now re-classified Jovian asteroid has a rotation period of 9.3 hours and belongs to the . It was named from Greek mythology after Periboea, mother of Pelagon by the river-god Axius.