Polaris, the star for December

This month look for the star Polaris, the lucida (brightest star) of Ursa Minor the Little Bear. Polaris is also known as Alpha Ursae Minoris, The North Star, The Pole Star, and The Lode Star. Polaris is the guide to true north (as opposed to magnetic north) so it appears nearly straight up to anyone standing on the North Pole. Polaris is not the brightest star in the sky nor is it exactly true north. Polaris is actually the 40th brightest star in the sky and ¾ of a degree (1-1/2 moon diameters) away from the point of true north in the sky. In long duration photographs, Polaris makes a tiny little circle around the true North Pole. Polaris is the star marking the end of the Little Dipper’s handle.

Polaris is a bit hotter than our sun and older. It’s at the point in its life where it is fusing helium in its core and fusing hydrogen in a shell above its core. This makes Polaris slightly unstable and its outer layers pulsate in size and slightly in brightest. At 430 light years away, you’re seeing light from Polaris that was emitted in the year 1584.

Polaris is an easy star to find since most people can locate the Big Dipper in the sky. The two stars at the end of the Big Dipper’s bowl are called the Pointers and a line drawn up from the Pointers just about runs into Polaris.