How do astronomers learn what elements are present in a given star?
A) look at what color light dominates its continuous spectrum
B) listen for coded signals in the radio waves it gives off in the FM band
C) look at the absorption lines in its spectrum
D) send spacecraft like Voyager to examine its make-up from close-up
E) compare visible-light photographs of the star (taken with large telescopes) to those of the Sun.

Question

Quizplus · Accepted Answer

Astronomers analyze the light of a star by separating it into its various colors to form a spectrum. This spectrum shows dark absorption lines, which correspond to the wavelengths of light that have been absorbed by specific elements in the star's atmosphere. By comparing these lines to known spectra of elements on Earth, astronomers can identify which elements are present in the star's atmosphere.

How Do Astronomers Learn What Elements Are Present in a Given