Final answer:
The star Thuban in Draco was an excellent north pole star in 3,000 BC, but it is no longer the center of the precession cycle. The current pole star is Polaris, which is used to locate the vernal equinox.
Step-by-step explanation:
The star Thuban in Draco is not the center of the precession cycle, but it was an excellent north pole star in 3,000 BC. The center of the precession cycle actually refers to the point around which the celestial sphere appears to rotate due to the wobbling of Earth's axis. The current pole star is Polaris, which is used to locate the vernal equinox. Thuban is not brighter than Polaris, and it does not lie halfway between the bowls of the Big and Little Dippers.