Which characteristic of a star's spectrum is most important in determining its spectral classification?

Question

Quizplus · Accepted Answer

The identification of the elements producing the spectral lines and their relative strengths is the most important characteristic in determining a star's spectral classification. This is because each element has a unique set of spectral lines, and the ratios of the strengths of these lines are indicative of the star's temperature, luminosity, and other properties. The number of spectral lines and the presence of emission or absorption lines can also provide important information, but the identification of the elements and their strengths is the primary factor. The Doppler shift can help determine the radial velocity of the star, but it is not directly related to spectral classification.

Which Characteristic of a Star's Spectrum Is Most Important in Determining