Henrietta Swan Leavitt
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Henrietta Swan Leavitt was an American astronomer. Her discovery of how to effectively measure vast astronomical distances led to a shift in the understanding of the scale and nature of the universe.
Leavitt, c. 1898
The observatory at Harvard where Henrietta Swan Leavitt worked.
Henrietta Leavitt (third from left) is shown working among "The Harvard Computers" who assisted astronomer Edward Charles Pickering at the Harvard College Observatory. The assistants also included Annie Jump Cannon, Williamina Fleming, and Antonia Maury.
Leavitt working at her desk in the Harvard College Observatory.
Period-luminosity relation
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In astronomy, a period-luminosity relation is a relationship linking the luminosity of pulsating variable stars with their pulsation period. The best-known relation is the direct proportionality law h
Henrietta Swan Leavitt
…discovery provided astronomers with the first standard candle with which to measure the distance to other galaxies. Before Leavitt discovered the period-luminosity relationship for Cepheid variables (sometimes referred to as Leavitt's Law), the only techniques available to astronomers for measuring the distance to a star were…
Plot from Leavitt's 1912 paper. The horizontal axis is the logarithm of the period of the corresponding Cepheid, and the vertical axis is its apparent magnitude. The lines drawn correspond to the stars' minimum and maximum brightness.
Phase lightcurve of variable star Delta Cephei.