Finding The North Celestial Pole
- See also Pole star, Polar alignment.
The north celestial pole currently is within a degree of the bright star Polaris (named from the Latin stella polaris, meaning "pole star"). This makes Polaris useful for navigation in the northern hemisphere: not only is it always above the north point of the horizon, but its altitude angle is always (nearly) equal to the observer's geographic latitude. Polaris can, of course, only be seen from locations in the northern hemisphere.
Polaris is near the celestial pole for only a small fraction of the 25,700-year precession cycle. It will remain a good approximation for about 1,000 years, by which time the pole will have moved to be closer to Alrai (Gamma Cephei). In about 5,500 years, the pole will have moved near the position of the star Alderamin (Alpha Cephei), and in 12,000 years, Vega (Alpha Lyrae) will become our north star, but it will be about six degrees from the true north celestial pole.
To find Polaris, face north and locate the Big Dipper (Plough) and Little Dipper asterisms. Looking at the "cup" part of the Big Dipper, imagine that the two stars at the outside edge of the cup form a line pointing upward out of the cup. This line points directly at the star at the tip of the Little Dipper's handle. That star is Polaris, the North Star.
Read more about this topic: Celestial Pole
Famous quotes containing the words finding the, finding, north, celestial and/or pole:
“Love has its own instinct, finding the way to the heart, as the feeblest insect finds the way to its flower, with a will which nothing can dismay nor turn aside.”
—Honoré De Balzac (1799–1850)
“As a father I had some trouble finding the words to separate the person from the deed. Usually, when one of my sons broke the rules or a window, I was too angry to speak calmly and objectively. My own solution was to express my feelings, but in an exaggerated, humorous way: “You do that again and you will be grounded so long they will call you Rip Van Winkle II,” or “If I hear that word again, I’m going to braid your tongue.””
—David Elkind (20th century)
“The Bostonians are really, as a race, far inferior in point of anything beyond mere intellect to any other set upon the continent of North America. They are decidedly the most servile imitators of the English it is possible to conceive.”
—Edgar Allan Poe (1809–1845)
“The mistake that men make is that they do not believe in theater. Otherwise, they would know that every man is allowed to play the celestial tragedies and to become god. All he has to do is harden his heart.”
—Albert Camus (1913–1960)
“I wouldn’t take the Pope too seriously. He’s a Pole first, a pope second, and maybe a Christian third.”
—Muriel Spark (b. 1918)