Which is one reason that the typical galaxy's mass-to-light ratio (in units of the Sun's mass over the Sun's luminosity) generally greater than 1?
A) galaxies contain mostly stars much brighter than the Sun
B) galaxies contain mostly stars much more massive than the Sun
C) galaxies contain many more stars that shine much less brightly than the Sun
D) most of the mass in a galaxy is in the form of dust
E) this is an unsolved problem in astronomy; scientists have no clue

Question

Quizplus · Accepted Answer

Galaxies contain a mix of stars with different masses and luminosities, but on average the majority of stars in a galaxy are smaller and fainter than the Sun. This means that the total mass in a galaxy is higher than the total luminosity, resulting in a mass-to-light ratio greater than 1.

Which Is One Reason That the Typical Galaxy's Mass-To-Light Ratio