If the nearest star is 4.2 light-years away,then
A) the star is 4.2 million AU away.
B) the light we see left the star 4.2 years ago.
C) the star must have formed 4.2 billion years ago.
D) the star must be very young.
E) the star must be very old.

Question

Quizplus · Accepted Answer

The term "light-year" refers to the distance that light travels in one year. Therefore, if a star is 4.2 light-years away, the light we see from it today left the star 4.2 years ago.

If the Nearest Star Is 4.2 Light-Years Away,then