The Pole Star meaning is the North Star or Polaris that lies closely in line with the axis of the Earth’s rotation “above” the North Pole, i.e., the north celestial pole.
The pole star or Polaris stands almost motionless or static in the sky, and all the stars of the northern sky surrounding this star appear to rotate around it. Therefore, it makes an excellent fixed point from which scientists draw measurements for celestial navigation and astrometry.
In this article, we will understand the polestar definition, how to find the pole star in detail.
Define Pole Star
The Pole star or polar star is the name of Polaris lies in the constellation of Ursa minor, as it is the star nearest to the earth’s celestial north pole that we can in the image below:
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So, basically, the Polaris is a multiple star system including Polaris A, a yellow supergiant in orbit with a smaller star Polaris Ab and they both lie in the orbit of Polaris B.
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Where is Pole Star Located?
When the earth rotates about its axis, the pole star ‘appears’ to remain stationary because the position of the earth remains unchanged with respect to the pole star. Pole stars are also known as Polaris or North Star.
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So no matter wherever we are residing on the earth and no matter what the time is, the position of the pole star remains on this axis. However, this is not the case with the other stars in the galaxy. Only, the pole star is visible from the northern hemisphere.
However, the Pole star will not last forever. For the last thousands of years, the earth’s axis has been rotating slightly. This is called ‘precession’ and this results in the pole star shifting from the axis. A time will come, the present pole star will vanish and some other star, which is lying on the axis of the earth at that time will become our new pole star.
Now, let’s understand how to find pole star:
How to Identify Pole Star?
To understand how to identify pole star or how to find pole star, we have a scenario to understand where the pole star is located.
Imagine a Blackball as Earth and the marked blue dot on the Ball represent the North Pole. Now, draw the Equator along with the circumference of the ball.
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Mark a black dot somewhere on the white wall that will represent the Pole Star.
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Now, hold the ball in your right hand in such a way that the blue dot on the blackball points directly towards the black dot on the wall. This pertains to the current position of how Earth and Pole stars are aligned in the universe.
Now, we will rotate the blue ball along with the North-pole (its marked axis).
We notice that the relative position of the dot on the wall, i.e., Pole star remains invariant with respect to the dot on the ball, i.e., North Pole.
Now, as we move a certain distance away from the blue dot on the Ball, i.e., the North Pole or head towards the Equator, still the relative position remains unchanged.
Fun Fact
Do you know that the distance between the Earth and the Pole star is 433 Light Years? So, in the actual situation, this relative position is difficult to signify. This is the sole reason why the pole star remains stationary in the sky.
Now, after crossing the Equator, what we do is, move towards the Southern Hemisphere, a straight line that joins the two points breaks directly.
At this moment, the pole star indicates the direction to the place where it becomes invisible. Therefore, it becomes difficult to say where the pole star is located.
What is Polaris?
Polaris is also known as the North star. It appears static in the sky because it is located near the line of the axis of the Earth that is projected into space.
It is only a bright star whose position relative to the rotating Earth remains unchanged, while all other stars appear to move in an opposite direction to that of Earth’s rotation under them.
At the North Pole, Polaris appears directly above with the other stars circling around it during the entire night. As we move south, i.e., away from the pole, Polaris appears further descended in the Northern sky but still remains at the center of daily stellar motions around it.
Below is the figure of the Polaris a.k.a the North star with other stars circling around it.
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Since there is no bright star in the South pole, the South Star exists in the universe. However, this is also true that the North star or the Polaris, or the Pole Star direction would always be towards the North because the Earth wobbles (moves unsteadily) like a top in its orbit.
Do You Know?
Polaris will eventually appear to move away from the pole and won’t be remaining a North Star after a period of 26,000 years.