We’re up to the letter “N” in our A-Z challenge tour of heavenly bodies. There is only one constellation that begins with an N, Norma, which is located in the southern sky and isn’t well known. But there is the “North Star” which is we’ll explore today. My apologies for readers living in the southern half of our globe because you may have never seen this star as it stands high over the Celestial North Pole. The star is also known as Polaris (from Polaris Stella, Latin for North Star, not to be confused with Stella Artois or “star of Artois, the brewer). It is actually a triple star. Polaris A is a super-giant, with Polaris Ab orbiting about 2 billion miles out and Polaris B is orbiting at a distance of 240 million miles. The star luminosity is 2500 times that of our sun, but because of the distance from earth (430 light-years) it is only the 50th brightest star in the heavens. Although the star seems to remain steady, it is just off the true celestial north, and actually tightly circles the globe.
|Time delay photo showing stars circling the North Star|
The North Star hasn’t always been the North Star (see letter D for Draco), nor will it remain the North Star forever. But we won’t have to worry about finding another north star during our lives as it will come the closest to the pole in 2100. During the age of exploration, the North Star helped ships as they made their way across the Atlantic and when slavery was allowed in the United States, the “Dippers” and the North Star guided those fleeing slavery as they made their way north and on to Canada.
Polaris is the last star in the handle of the Little Dipper (Ursa Minor of the Little Bear). It can be easily found by looking at the two stars at the cup end of the Big Dipper and following them to Polaris. On a dark night, one can see the entire little dipper constellation. The constellation, Ursa Minor or “The Little Bear” represents Arcas, Callisto’s son by Jupiter. When Jupiter decided to place Callisto in the sky, he placed her son next to her, changing them into a bear. I suppose Jupiter wasn’t just a seducer of mortals, he had a heart as seen in this kind act.