Which of the following quantities is most useful to astronomers when measuring the dark matter content of galaxies?
A) color
B) age
C) stellar velocities
D) luminosity

Question

Quizplus · Accepted Answer

Stellar velocities are most useful for measuring the dark matter content of galaxies. This is because the gravitational pull of dark matter affects the motion of stars in a galaxy, causing them to move at higher velocities than expected based on the visible mass alone. By studying the velocities of stars in a galaxy, astronomers can determine the amount of dark matter present. Color, age, and luminosity are all properties of stars that can provide useful information for astronomers, but they are not directly related to measuring the dark matter content of galaxies.

Which of the Following Quantities Is Most Useful to Astronomers