Why is an absorption spectrum especially useful for astronomers?
A) It has dark lines in it that allow astronomers to determine what elements are in the star
B) It has bright lines in it which allow astronomers to determine how bright the star is
C) It helped astronomers to understand the rainbows we see on Earth after storms
D) It shows that the stars are transparent; we can see right through them
E) An absorption spectrum is not useful to astronomers at all. When they see one, it means they cannot learn anything about the stars that produced the annoying absorption.

Question

Quizplus · Accepted Answer

An absorption spectrum has dark lines in it caused by specific elements absorbing photons at certain wavelengths. By comparing these spectral lines to known spectra of elements, astronomers can determine what elements are present in the star being observed. This is important for understanding the chemical makeup of stars and galaxies, as well as for identifying exoplanets and other astronomical objects.

Why Is an Absorption Spectrum Especially Useful for Astronomers