Cepheid variable stars are invaluable in astronomy because of the close relationship between
A) the peak wavelength of their spectra and their surface temperatures.
B) their luminosity, or absolute magnitude, and their pulsation period.
C) the redshift of their spectra and their distance from the Sun.
D) their apparent magnitude and their pulsation period.

Question

Quizplus · Accepted Answer

Cepheid variable stars are crucial for distance measurement in astronomy due to the direct relationship between their intrinsic brightness (luminosity or absolute magnitude) and their pulsation period. This relationship allows astronomers to determine the distance to Cepheids by observing their pulsation period and calculating their true brightness.

Cepheid Variable Stars Are Invaluable in Astronomy Because of the Close