Cepheids | Sebastian Spicker

2025

1 article

3 Mar 2025 Twenty-Five Stars and the Scale of the Universe Henrietta Leavitt found a relation between the periods and brightnesses of twenty-five variable stars. Reconstructing her 1912 data shows why a shared distance makes the discovery possible, why a calibration is still missing, and why measuring photographic plates was intellectual work rather than a preliminary step before the science began. astronomyhistory-of-sciencegender