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

Question

Quizplus · Accepted Answer

Type Ia supernovae have approximately the same luminosity, which means they can act as "standard candles" for measuring distance. By comparing the apparent brightness of a Type Ia supernova to its known luminosity, astronomers can determine how far away it is, and therefore how far away its host galaxy is.

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