On the basis of the graph of absorption line strengths in spectra of stars presented in Figure 17-12, what is the spectral type of a star with the following spectral pattern: very strong H, weaker Mg II and Si II, and no He I or Ca II lines?

Question

Quizplus · Accepted Answer

The spectral pattern described matches that of a type A star, characterized by very strong hydrogen lines, weaker magnesium (Mg II) and silicon (Si II) lines, and the absence of helium (He I) and calcium (Ca II) lines.

On the Basis of the Graph of Absorption Line Strengths