The north star Polaris is an important tool in navigation. The angle between the northern horizon and Polaris gives the latitude. This useful tool was heavily used by travelers in the past to determine where they were. In the ancient world, it was even used to help people find their way to the north pole. Today, it is an essential tool for all travelers. The following article will discuss the importance of Polaris. It can also be helpful in locating the northern limit of the Earth’s rotation.
The star Polaris is a multiple star system. It is comprised of several stars, the main one being a yellow supergiant star with spectral class F7. It has a diameter of 46 times that of the Sun and is 2,500 times more luminous than the Sun. It is classified as a Cepheid variable and shows pulsations every four days. It has been used for navigation since late antiquity.
The magnitude of Polaris varies from 1.86 to 2.13. Before the year 1963, the star had an amplitude of more than 0.1 magnitude. Gradually, the brightness increased until 1966, when it suddenly decreased dramatically to only 0.05 magnitude. Since then, the brightness has fluctuated unpredictably and has remained near that of 1966. In 2008, another paper published the results of another study that stated that the amplitude of Polaris was increasing.
In the late 1800s, the star was discovered by Sir Isaac Newton. Its diameter has changed dramatically since its discovery. It has decreased from third magnitude to second magnitude. This sudden change is so dramatic, in fact, that astronomer Edward Guinan has said it is 100 times greater than the changes predicted by current theories of stellar evolution. As a result, the star is now the brightest object in the sky. The star’s position is extremely important in determining the distance of galaxies and the expansion rate of the universe.
Scientists plan to observe the Polaris system for several years. During this time, the light of Polaris should be at the same brightness as the light of its companion, a comet named Lovejoy. This is the reason why the light of Polaris is important in navigation. It is important to note that the light from the comet is not equivalent to the light from the sun, because the two stars are so far apart. Consequently, the two stars’ positions may not be the same.
In addition to the primary star, the stars of the constellation Polaris are the brightest stars in the Magellanic Clouds. In 1909, Danish astronomer Ejnar Hertzsprung discovered that Polaris was a variable star. In 1911, he also determined the distance of several other variable stars using parallax. These discoveries confirmed the theory of binary stars. This discovery proved to be very important for astronomy.
The brightness of Polaris is a very sensitive indicator of its age. The first person to notice it is William Herschel in 1779. The star is very bright, but it is in fact quite old. It has changed its brightness since its discovery. A few years ago, it had a magnitude of over one. However, its brightness had dropped dramatically by the end of the century. The same phenomenon happened after the star was discovered in 1908.
The distance of Polaris is 18 arc seconds from the primary star. This star is the closest star to the Earth. Its light is three times brighter than the Sun. During classical antiquity, the celestial pole was near the stars of the Andromeda Galaxy. In the present, it is about the same distance from the Sun. The distance between the stars is measured with the help of the relation between the luminosity and period.
Researchers have observed changes in the amplitude of Polaris since its discovery. The light that the star casts on Earth is low-amplitude. Its period, which is about 50 seconds, has a constant period. This star’s pulsations have increased and decreased over time. Until the early medieval period, Polaris was not bright enough to be seen. The brightest stars were the stars of the Andromeda Galaxy.