The pole star belongs to the constellation Little Dipper. It is at distance of 431 light years from Earth and represents a threefold star system which consists of the giant Polar And yes a small star of Ab and also remote from them Polar Century.
Pole star in the sky
By means of a pole star it is possible to define on the area where there is a North. At first it is necessary to find a ladle of Big Dipper, it consists of seven bright stars. Through two stars opposite to the handle of a ladle, Merak and Dubkhe, it is necessary to draw the imagined line up. Then at the distance equal to five intervals between these stars, it is possible to find the Pole star. It is on the end of the handle of a ladle of the constellation Little Dipper.
The pole star has strong gloss, however in the list of the brightest stars of the sky it takes only the 48th place. It surpasses the Sun in the sizes by 2000 times and belongs to giant stars, its weight by 6 times, and luminosity by 2400 times exceeds solar. Temperature on its surface — about 7000 To.
Constellation Little Dipper
The constellation in which there is a Pole star is called Little Dipper, its area is 255.9 sq. degrees. Under ideal conditions of observation in it it is possible to notice 25 stars. The North Pole of the world is located near the Pole star, but so was not always. Because of the phenomenon of a precession is the in the ancient time closest to it the star Kokhab, a beta of Little Dipper was located. Even earlier, about 4000 years ago, function of a pole star was performed by Tuban, the Dragon alpha. The most remarkable detail of the constellation is the asterism the Small Ladle, 7 stars enter it. It is not so noticeable as a ladle of Big Dipper which is visible in the winter and in the fall in the north low over the horizon. In the spring evenings it can be found in the east, at this time he settles down vertically — the handle down. It is easy to see a ladle in the summer in the West when it is located the handle up. The ladle of Little Dipper lasts towards a ladle Big. Its stars strongly differ in gloss, only 3 of them it is possible to find easily in the city sky — Polar and also Kokhab and Ferkad. The others 4 - are much more dim, they are visible not always. The small Ladle at all seasons of the year and day is approximately in the same part of the star sky.
Other stars of Little Dipper
Kokhab, or a constellation beta Little Dipper, on the gloss is close to the Pole star. It has pronounced orange color, it belongs to spectral class K. This star is colder than the Sun, but by the sizes it is more of it by 40 times. Ferkad — the third in brightness in this constellation, is hotter than Kokhab and the Pole star, however considerably concedes to them in gloss as is further — at distance of 500 light years from Earth. Ferkad and Kokhab forms asterism Guards Polyusa.