Question

Explain parallax method for measuring distance of a nearly star.

Answer 1

This problem can be solved by drawing a proper diagram by visualisation of position of earth and nearly star. Parallax is a method based on measuring two angles and sides of a triangle formed by the star, earth on one side and other side six month later. Astronomers find the distance of nearby stars in space by using a parallax method.

Formula used: Parallax Formula
$d = 1/p$
Here $d =$ the distance to the star (in parsecs)
$P =$The parallax angle of the star (in arc seconds)

Complete step by step answer:
Parallax is a method based on measuring two angles and sides of a triangle formed by the star, earth on one side and the other side six month later. Astronomers find the distance of nearby stars in the space by using a parallax method.
First let us draw a diagram to understand the problem better.

Astronomers use an effect to find the distance to a nearby star. Its apparent displacement by comparing the distance of star respect to the earth. Step-1 See the position of an object (nearby star) once and then again six month later.  Step-2 calculate the change in position by finding the angle of parallax There is simple relation between star distance and its parallax Parallax Formula $d = 1/p$ Here $$d = $$ the distance to the star (in parsecs) $$P = $$ The parallax angle of the star (in arc seconds) Parallax second :- A star when covering a distance of 1 arc second has equal to the 1 parallax sec(parsec). 1 parsec is equal to the $$3.26{\text{ }}light{\text{ }}years$$ Light year:- It is important to find the distance. One light year is equal to the distance travelled by light for one year. 1 degree parallax angle is equal to $$3600{\text{ }}arc{\text{ }}second$$ The sun nearest star distance =$$1.2948{\text{ }}pc$$ The earth nearest star distance =$$1.2948{\text{ }}pc$$ The Pluto nearest star distance =$$1.2948{\text{ }}pc$$ Limitation: If the star has too much distance then parallax angle will become very small to measure and less precise the distance measurement. **Note:** The best way to solve problems of optics is to draw diagrams. This helps in visualizing the problem clearly. You should have a good knowledge of angle and radius. You should have to calculate the angle after six month.