Question

how do spectrographs help astronomers classify stars?
○ they determine the size of stars.
○ they evaluate the color of stars.
○ they measure the brightness of stars.
○ they analyze the composition of stars.

Explanation:

Spectrographs work by analyzing the light from stars to identify the elements present (composition) based on spectral lines. Determining size, evaluating color, or measuring brightness are not the primary functions of spectrographs for star classification related to their internal makeup.

Answer:

D. They analyze the composition of stars.