Henrietta Swan Leavitt Quote

Since the [Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual emission of light, as determined by their mass, density, and surface brightness.


Periods of 25 Variable Stars in the Small Magellanic Cloud (1912)


Since the [Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual...

Since the [Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual...

Since the [Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual...

Since the [Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual...