How can we see stars that no longer exist?

1 Answer

Light travels through vacuum at a particular speed 300,000 KM/sec.


So a distant object you are seeing now may not be there now.The light that is reaching your eye is thousands of year old.
For example the brightest star Sirius is 8.2 light years away..So the light that reach your eyes now is 8.2 years old(Left the star 8.2 years back)..So you will continue to see Sirius for 8.2 years even after the star dies.