GENERAL KNOWLEDGE

Detailed explanation-1: -By carefully measuring the angle through which the stars appear to move over the course of the year, and knowing how far Earth has moved, astronomers are able to use basic high-school geometry to calculate the star’s distance.

Detailed explanation-2: -Light-year is a large unit and equals the distance travelled by light in one year. Hence, the large distances are expressed in light-years. If a star is located 8 light-years away from the earth, it means that the distance between the star and the earth is the distance light would travel in eight years.

Detailed explanation-3: -The average distance between galaxies is about one million light years. There are roughly 100 billion galaxies in the observable universe. Another, often-used unit of distance is the parsec. One parsec is approximately 3.26 light-years.

Detailed explanation-4: -Parsecs: Many astronomers prefer to use parsecs (abbreviated pc) to measure distance to stars. This is because its definition is closely related to a method of measuring the distances between stars. A parsec is the distance at which 1 AU subtends an angle of 1 arcsec.