Henrietta Swan Leavitt

Astronomer who discovered the period-luminosity relationship of Cepheid stars, enabling cosmic distance measurement

Henrietta Swan Leavitt (1868-1921) transformed astronomy while working as a Harvard College Observatory 'computer'. Despite being paid 30¢/hour and denied telescope access, she analyzed thousands of stars in the Magellanic Clouds.

Her 1912 discovery that Cepheid variable stars have predictable brightness cycles (Leavitt's Law) became astronomy's 'standard candle'. This allowed Edwin Hubble to prove galaxies exist beyond the Milky Way and measure cosmic expansion. NASA credits her work as foundational to modern cosmology.

Though barred from academic positions due to gender, Leavitt's meticulous data analysis created new cosmic yardsticks. The American Association of Variable Star Observers maintains her legacy. Her silent revolution in measurement methodology continues shaping space exploration today.