Who first determined that the energy/s emitted by (luminosity of) Cepheid variable stars is larger the longer their period of variation is
A)Henrietta Leavitt
B)Edwin Hubble
C)John Glenn
D)Carl Sagan
E)Harlow Shapley

Question

Quizplus · Accepted Answer

Henrietta Leavitt first discovered the period-luminosity relationship of Cepheid variables in 1912 while studying photographic plates of the Large Magellanic Cloud at Harvard College Observatory. Her discovery was later used by Edwin Hubble to determine the distance to other galaxies and support the theory of an expanding universe.

Who First Determined That the Energy/s Emitted by (Luminosity Of)