What is the North Star?
The North Star, also called Polaris, is the star that sits almost directly above Earth's North Pole. It appears to stay still while other stars circle around it, making it useful for navigation.
Polaris lies very close to the point in the sky that Earth's axis points toward, called the north celestial pole. As Earth rotates, all other stars seem to circle around it, while Polaris stays nearly fixed. If you face Polaris, you are facing north, and its height above the horizon roughly equals your latitude.
Polaris is not the brightest star in the sky, as many people think. It ranks around 48th in brightness. It is the end star in the handle of the Little Dipper. It is actually a multiple star system about 430 light-years away, with a yellow supergiant as its main star.
A changing North Star
Earth's axis slowly wobbles in a cycle lasting about 26,000 years, a process called precession. Around 3000 BC, the star Thuban was the pole star. In about 12,000 years, the bright star Vega will be close to the north celestial pole.
Did You Know?
You can find Polaris by following the two stars at the end of the Big Dipper's bowl, called the Pointers, upward about five times their distance apart.