What crucial physical link concerning Cepheid variables was discovered by Henrietta Swan Leavitt?
Answer
The longer a Cepheid's pulsation period, the greater its intrinsic luminosity
Henrietta Swan Leavitt established the critical period-luminosity relationship for Cepheid variable stars. This discovery provided the necessary bridge between observation and cosmological measurement. By measuring how long it took for a Cepheid to cycle between its brightest and dimmest phases (its pulsation period), astronomers could determine its absolute, true brightness, regardless of its distance, which is essential for using it as a standard candle.
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