On the main sequence,a star's spectral type is ultimately determined by its:
A) distance.
B) luminosity.
C) composition.
D) mass.

Question

Quizplus · Accepted Answer

A star's spectral type is ultimately determined by its mass. This is because a star's mass determines its internal temperature, which in turn determines the spectrum of radiation emitted by the star. The spectral type is a classification of a star based on the lines observed in its spectrum, and these lines are determined by the temperature of the star, which is primarily determined by its mass. The other options, distance, luminosity, and composition, can be important factors in understanding a star's properties, but they do not ultimately determine its spectral type.

On the Main Sequence,a Star's Spectral Type Is Ultimately Determined