Why are the youngest galaxies that are seen in distant parts of the universe bluer and brighter than the older, closer galaxies observed?
A) The red light has been partially absorbed by gas and dust between Earth and the galaxies.
B) Young galaxies have more dust, and dust scatters blue light better than red.
C) The light from the most distant galaxies has been bent by gravitational lenses and focused on Earth.
D) Young galaxies have a burst of star formation that produces many hot, bright, blue stars.

Question

Quizplus · Accepted Answer

Young galaxies are observed to be bluer and brighter primarily because they are undergoing bursts of star formation, which produce many hot, bright, blue stars. These stars emit most of their energy in the blue part of the spectrum, making the galaxies appear bluer and more luminous.

Why Are the Youngest Galaxies That Are Seen in Distant