Why can Type I supernovae be used to determine a galaxy's distance?
A) Type I supernovae occur only in very luminous galaxies.
B) Type I supernova have approximately the same luminosity.
C) Type I supernovae have approximately the same size.
D) A Type I supernova occurs in a typical galaxy about once every 100 years.

Question

Quizplus · Accepted Answer

Type I supernovae have a consistent luminosity, which makes them useful as "standard candles" for measuring distances in the universe. By observing the apparent brightness of a Type I supernova in a distant galaxy, astronomers can determine how far away the galaxy is.

Why Can Type I Supernovae Be Used to Determine a Galaxy's