What is Polaris?

Polaris, also known as North Star because of its proximity to the heavenly pole, is the brightest star in the constellation Ursa Minor, The Little Bear and The Little Dipper. Polaris can be found by expanding the imaginary line from the two farthest real stars in the large diet "up" from the "ladle" of the ladle and immediately finding a very bright star on this line. Polaris was historically used slaves in the American South, who tried to escape north through the underground railway. Therefore, the folk song “Watch The Pinking Gourd”. "Drinking gourd" concerns a large ladle. Of course, the name Polaris comes from its position of the polar star.

Polaris is a giant star containing five and six solar materials. It has a diameter of 60 solar radii AMA luminosity 2200 times larger than the sun. Its surface temperature is 7700 hp, significantly warmer than the sun.

Polaris is not exactly aligned with the heavenly pole (a axis of the bikem, which seems to be the stars in the night sky), but in fact it is removed 0.7 °, about 1 1/2 width of the moon. Polaris cannot therefore be relying on extremely accurate direction estimates to the north if the time -lapse exposure of its movement in the sky cannot be carried out. Polaris will not be closest to the northern heavenly pole due to changes in the axis of the Earth's rotation due to the plane of the elliptics.

There is no real star of the South Pole, as if Polaris was for the star of North Field, although the asterism of the southern cross almost directly to the southern celestial pole.