Light Year Question: When Will We See It?

[roxxyroxx]

Homework Statement

If a star explodes 30 light years from the Earth when will we be able to see it?

Homework Equations

one light year = 9.47 x 10¹²km
speed of light = 3.00 x 10⁸m/s

The Attempt at a Solution

the answer in my workbook says 30a but idk what the value of a is

 

[EstimatedEyes]

The definition of light year tells us that light will take 30 years to travel that distance, so the answer is indeed 30 years.

 

[Astronuc]

a could be an abbreviation for annum (year) or anni (years).