Henrietta L. Leavitt

Henrietta L. Leavitt was an astronomer in the early 20th century who made a groundbreaking discovery. She studied a type of star called Cepheid variables, which brighten and dim regularly. By measuring their brightness and timing their cycles, she found a direct link between the period of their variability and their true brightness. This relation allowed astronomers to determine the distance to faraway galaxies accurately. Leavitt's work provided a crucial tool for measuring the scale of the universe, helping scientists understand how vast and old the cosmos truly is.