Question

**HELP ASAP PLEASE!**

How can astronomers determine a star’s chemical composition?

A.by looking at its temperature

B.by using a spectrograph

C.by comparing its size to the sun

D.by comparing its color to the sun

Answer 1

I think, according to Neil DeGrasse Tyson's Cosmos, that it would be either A. or B. That should eliminate the answers that I am pretty sure don't make sense. Though I am pretty sure it should be A......

P.S. You should watch Cosmos! It's pretty good!

Answer 2

They use a spectrograph so the answer would be B.