Which of the following is NOT evidence of the existence of an interstellar medium
A)extinction of light from distant stars
B)very narrow calcium absorption lines in the spectra of O and B stars
C)reddening of more distant stars
D)dark cloud silhouetted against background stars
E)molecular absorption lines in the spectra of cool stars

Question

Quizplus · Accepted Answer

Molecular absorption lines in the spectra of cool stars are not evidence of the interstellar medium. These lines are typically associated with the atmospheres of the stars themselves, rather than with material between the stars.

Which of the Following Is NOT Evidence of the Existence