Henrietta Swan Leavitt quotes

A straight line can readily be drawn among each of the two series of points corresponding to the maxima and minima, thus showing that there is a simple relation between the brightness of the variables and their periods. (Henrietta Swan Leavitt)
It is hoped that systematic study of the light changes of all the variables, nearly two thousand in number, in the two Magellanic Clouds may soon be undertaken at this Observatory. View quote
Henrietta Swan Leavitt
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. View quote
Henrietta Swan Leavitt
The discovery of variable stars. View quote
Henrietta Swan Leavitt
Apparently no sharp dividing line can be drawn between true Algol stars and those whose variations are continuous. Periods of nine variables in this region, which are of the Algol type or closely resemble it, have been determined and are here discussed. View quote
Henrietta Swan Leavitt
It is to be hoped, also, that the parallaxes of some variables of this type may be measured. View quote
Henrietta Swan Leavitt
It is worthy of notice that in Table VI the brighter variables have the longer periods. It is also noticeable that those having the longest periods appear to be as regular in their variations as those which pass through their changes in a day or two. View quote
Henrietta Swan Leavitt