Stars of spectral type O, the hottest blue-white stars, have spectra characterized by
A) the strongest hydrogen lines of any spectral type.
B) spectra of complex molecules.
C) very few spectral lines.
D) very intense spectral lines all across the spectrum.

Question

Quizplus · Accepted Answer

Stars of spectral type O are very hot and thus ionize most of their atoms, leading to very few spectral lines in their spectra. The high temperatures prevent the formation of complex molecules, and while they do have hydrogen lines, these are not the strongest among the spectral types.

Stars of Spectral Type O, the Hottest Blue-White Stars, Have