Question

Explain with a diagram how you can locate pole star with the help of the constellation Great Bear (Ursa Major).

Answer 1

Pole Star

1. It is a bright star that can be seen in the sky in northern parts of the world when one looks directly toward the north.
2. The Pole star is the shiniest star in the constellation Ursa Minor.
3. The position of the pole star relative to the earth is constant & thus it was the ideal start to look for direction in ancient times.
4. It is very close to the northern pole, thus used to indicate the north pole. - Hence, polestar is an important tool for skywatching.

Position of the pole star.

1. Find out two stars (shown in the figure) that are part of the quadrilateral near one end of the Ursa constellation.
2. These two stars are on the right part of the rectangle shown in the figure and they lie vertically opposite to each other.
3. Imagine a straight line joining these two stars.
4. Then extend this imaginary line towards north nearly four-five times the distance between these two stars.
5. This line will lead to the bright Pole star or north star.

Diagrammatic representation:

Thus, we can identify polestar in this simple way.