Polaris

Polaris: Commonly called the North Star, Polaris happens to be near perfectly aligned with Earth’s North Celestial Pole. For centuries, Polaris has been used to navigate all over the world, however, it wasn’t always the North Star. The Earth wobbles on it axis very slowly in a process called procession. Because of this, the axis points to different stars over thousands of years. This means that at one point, another star used to be the north star, and one day a different star will be the North Star. Don’t worry though, because these stars are in a constant rotation. So even though in a few thousand years Polaris won't point North, it will a few thousand after that.
Artist Rendition of Polaris Triple Star System. Image Credit: Space.com
At first glimpse, Polaris seems like a dim, unimportant star (it's far from being the brightest star in the sky) but if you pull back the layers, there is a lot to this star. Polaris is famous because it is due North, however this isn’t actually true! Polaris is very close to the North Celestial Pole (due north and where Earth’s northern axis points) but it is actually off by a little less than 1 degree. But don’t worry, unless you’re doing astrophotography, this will have no effect on your stargazing experience. Polaris has another secret: it isn’t alone. Once optical aid was made available it was obvious there was another star orbiting Polaris. It was another surprise though, when a 3rd star was discovered very close to Polaris. This star is so close to the pole star that even the Hubble Space Telescope was barely able to find it! Polaris isn’t even a “typical” star because it is a special type of variable star called a Cepheid variable. This means that Polaris brightens and dims on a very specific cycle so that astronomers are able to judge its distance quite easily (433.8 light years for Polaris.) Polaris is clearly much more than that dim light in the North!


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How to find Polaris. Image Credit: Richard McDonald

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