Her discovery provided astronomers with the first "standard candle" with which to measure the distance to faraway galaxies. Cepheids were soon detected in other galaxies, such as Andromeda (notably by Edwin Hubble in 1923–24), and they became an important part of the evidence that "spiral nebulae" are independent galaxies located far outside of our own Milky Way. Leavitt's discovery provided the basis for a fundamental shift in cosmology, as it prompted Harlow Shapley to move our Sun from the center of the galaxy in the "Great Debate" and Hubble to move our galaxy from the center of the universe. With the period-lumnosity relation providing a way to accurately measure distances on an inter-galactic scale, a new era in modern astronomy unfolded with an understanding of the structure and scale of the universe. The discovery of the expanding universe by Georges Lemaitre and Hubble were made possible by Leavitt's groundbreaking research. Hubble often said that Leavitt deserved the Nobel Prize for her work, and indeed she was nominated by a member of the Swedish Academy of Sciences in 1924, although as she had died of cancer three years earlier she was not eligible. (The Nobel Prize is not awarded posthumously.)