Hubbld's Sepiad Formula - The Nebula of Andromeda

Hubble observed his first variable in and Andromeda brightening by more than a magnitude doubling its luminosity. The star was seven thousand times brighter than our own sun, but it appeared so dim that hubbld knew it had to reside at a great distance. And on february nineteenth, 19 24, hubble wrote shapley a letter announcing his findings. He used the exact same technique for gauging a distance to the spiral that shapley had devised for mapping the arrangement of globular clust s around the milky way. In other words, hubble politely threw shapley's own sepiad formula back in his face and showed that andromedathat the