HENRIETTA SWAN LEAVITT.

The article focuses on Henrietta Swan Leavitt's significant contributions to astronomy, particularly her discovery of the period-luminosity relationship of Cepheid variable stars. Born in 1868 in Massachusetts, Leavitt worked as a 'human computer' at Harvard College Observatory, where she identified thousands of variable stars and established that their brightness correlated with their pulsation periods. This groundbreaking finding allowed astronomers to use Cepheids as distance markers, fundamentally changing our understanding of the universe and leading to the realization that the Milky Way is just one of many galaxies. Leavitt's work laid the groundwork for future astronomical discoveries, despite her facing challenges such as hearing loss and limited recognition during her lifetime. [Extracted from the article]