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Henrietta Swan Leavitt discovered that Cepheid variable stars reveal their intrinsic brightness through their pulsation periods, making them crucial distance markers for the universe.

Cepheids and the cosmic distance scale

BiographySpaceScience

Why it matters

The idea in context

Leavitt worked with photographic plates, not rockets or radio dishes, yet her insight expanded the universe. By noticing that Cepheid variables with longer periods were intrinsically brighter, she gave astronomers a way to compare true brightness with apparent brightness and calculate distance. Hubble later used that ladder to show galaxies rushing away. A patient pattern in glass plates became a measure for cosmic scale.

Türkçe

Aynı kart, başka bir dilde.

Henrietta Swan Leavitt, Sefeid değişen yıldızlarının titreşim dönemleriyle gerçek parlaklıklarını gösterdiğini keşfetti; böylece onları evren için kritik uzaklık işaretlerine dönüştürdü.
Sefeidler ve kozmik uzaklık ölçeği

Leavitt roketlerle ya da radyo çanaklarıyla değil, fotoğraf plakalarıyla çalıştı; yine de içgörüsü evreni genişletti. Daha uzun dönemli Sefeid değişenlerinin özünde daha parlak olduğunu fark ederek astronomlara gerçek parlaklık ile görünen parlaklığı karşılaştırıp uzaklık hesaplama yolu verdi. Hubble daha sonra bu merdiveni galaksilerin uzaklaştığını göstermek için kullandı. Cam plakalardaki sabırlı bir örüntü, kozmik ölçeğin ölçüsüne dönüştü.

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Background reading: Henrietta Swan LeavittAttribution and context are revised when stronger evidence appears. Corrections are welcome through the editorial page.
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