What is the primary form of evidence that has led astronomers to conclude that the expansion of the universe is accelerating?
A)observations of the speeds of individual galaxies in clusters
B)measurements of the rotation curve for the universe
C)measurements of how galaxy speeds away from the Milky Way have increased during the past century
D)observations of white dwarf supernovae

Question

Quizplus · Accepted Answer

Observations of white dwarf supernovae have been used as a primary form of evidence for the acceleration of the expansion of the universe. These supernovae occur when a white dwarf star, which is the remnant of a low-mass star, accretes matter from a companion star until it reaches a critical mass and undergoes a runaway nuclear fusion reaction that explodes the star. These explosions are thought to be uniform in brightness, and by measuring their apparent brightness from Earth, astronomers can determine their distance. Observations of distant supernovae have shown that they are fainter than expected if the expansion of the universe was slowing down, indicating that the expansion is accelerating.

What Is the Primary Form of Evidence That Has Led