Question

A star is 15 light year away from earth the light emitted by it today will be seen after how many years

Answer 1

Answer:

Explanation: we can see it in a few seconds

Answer 2

The light will be seen after 15 years.

Given,

Distance from the earth to the star is 15 light years.

If the stars emits light today,

Distance it needs to travel to be visible on earth is 15 light years

Definition of light year :

A light year is the unit of distance and is equal to the distance traveled by the light in vacuum in one year.

By this convention,

To travel 1 Light year - it takes 1 year

To travel 15 Light years - it takes 15 years.

So The light will be visible on earth after 15 years, that is the time light will require to travel from star to earth.