Discovery · 1912 CE
The Cepheid Period–Luminosity Relation
History of Astronomy
Overview
Henrietta Leavitt found that the pulsation period of a Cepheid variable star reveals its true luminosity, giving astronomers a 'standard candle' for measuring distance.
Why it matters
The key that let astronomers measure the scale of the galaxy and the universe beyond it.
Credit
Knowledge connections
- Discovered byHenrietta Swan Leavitt
- Part ofModern Astronomy
- Associated withThe Cepheid Distance Scale
Sources & references
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
- BritannicaEncyclopaedia Britannica
General reference for the history of astronomy, biographies, and cultural context.