Here is a small guide to recognize the North Star and thus distinguish the North. It is Polaris, the only immobile star in the sky that indicates the North.
When we have no compass and it is not possible to have the Sun, we can turn to the North Star to find the North. Polaris is the only star that remains motionless in the sky indicating the position of the North. Polaris is the brightest, closest to the North Pole and has a triple star system in the Ursa Minor. Inside stands out the yellow supergiant Polaris A, its distance from us is 325 light years. It is different from the others because it is very close to the North celestial pole. So it stands still as the hours and seasons pass. So much so that in a very short period of time it is impossible to notice the Earth’s rotation and the movement of the stars on the celestial sphere.
Its motion therefore fails to distinguish it from the others. However, she is not the brightest in the sky. How then to distinguish it? It is the brightest star of the Ursa Minor , which has the name of Little Dipper. To find it, it is useful to look for the Big Dipper or Big Dipper, as Polaris is perfectly aligned with the last two stars of the Big Dipper. A distance of 5 times the space that divides the two stars .
Excluding the period from September to December, Polaris can always be seen in the rest of the year. It is excluded in this period, because the Big Dipper (the one who helps to see the North Star) is low on the northern horizon. Once you have found the Big Dipper , you go in search of Dubhe and Merak, two stars. On their imaginary line we continue towards the arrow created by the stars Alioth, Mizar and Alkaid. The first star we will meet will be Polaris.
Alternatively, you can use the reference of the constellation of Cassiopeia , with an M or W shape. Once you have identified Cassiopeia you will have to look in the direction of the arrow of the stars Ruchbah, γ Cas and Shedir. The first shining star will be the North Star .
- How to recognize the Pole Star in the night sky? (scientenotizie.it)