Ursa Minor (the little bear) contains one of the most important stars in the heavens: Polaris, commonly known as the North Star. The star is found at the end of the backwards handle of the Little Dipper, which is actually the very long tail of the Little Bear.The easiest way to locate the North Star is to use the two stars on the front of the bowl of the Big Dipper, (which is part of the constellation Ursa Major, the Big Bear), as pointers.

Polaris just happens to be positioned almost exactly where Earth's northern axis points off into space, so as Earth turns on its axis, Polaris appears to stand still, and all the other stars seem to rotate around it. Since Polaris can always be found virtually in the same place, it is a perfect, steadfast beacon that has guided travellers through the ages.

In 1780, Astronomer William Herschel discovered that Polaris had a small companion star revolving around it, named Polaris B, making it a binary, or two-star system, as seen in the Hubble photo below left. In January, 2006, the Hubble Space Telescope found a third star, named Polaris Ab, orbiting much nearer Polaris A, shown in the close-up image below right. This new star makes Polaris now a triple star system.

The Polaris system is 430 light years away. Polaris A is a supergiant star, 2,000 times brighter than our Sun. Polaris B is a much smaller main sequence star orbiting Polaris A at a distance of 240 billion miles. The new discovery, Polaris Ab, is also an average main sequence star, much like our Sun. And although from our vantage point it appears to be right beside Polaris A, it is actually over two billion miles away from it.

The two stars that form the front of the bowl of the Little Dipper, named Kochab and Pherkad, are known as the Guardians of the Pole.

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