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Why isn't the North Star the brightest star?

When I was a very young boy an uncle of mine took me out on a balmy summer evening, pointed to a brilliant blue-white star directly overhead and said: "See that? That's the North Star" (I later would learn that it was actually Vega, the fifth brightest star in the entire sky).

Granted, Polaris, the real North Star. is probably the most important star visible in the northern sky. Yet many people are under the mistaken impression that it's also the brightest. It actually ranks only 49th in brightness and, for most viewers, is not directly overhead.

Polaris is the closest bright star relative to the north celestial pole. Only the apparent width of about 1½ full Moons separates Polaris from the pivot point directly in the north around which the stars go daily, as seen from any vantage point in the Northern Hemisphere.

Interestingly, because of the wobbling motion of the Earth's axis (called precession) the celestial pole will draw even closer to Polaris (closest in the year 2100), but then as time wears on it will gradually draw away from it. In fact, in about 12,000 years our descendants will have Vega as the North Star. My uncle will be happy to hear that.

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