Hеnriеttа Swаn Lеаvitt (Julу 4, 1868 – Dесеmbеr 12, 1921) wаѕ an Amеriсаn аѕtrоnоmеr whо diѕсоvеrеd thе relation bеtwееn thе luminоѕitу and thе реriоd оf Cepheid Full Biography
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. 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.
It is to be hoped, also, that the parallaxes of some variables of this type may be measured. Henrietta Swan Leavitt
It is to be hoped, also, that the parallaxes of some variables of this type may be measured.
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. 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.
In H 1255, the change in brightness is obviously continuous throughout the period, although it is much more rapid near minimum than near maximum. Henrietta Swan Leavitt
In H 1255, the change in brightness is obviously continuous throughout the period, although it is much more rapid near minimum than near maximum.
It seemed necessary, therefore, to take unusual precautions in order to secure accurate observations, and to give each one its full weight. Henrietta Swan Leavitt
It seemed necessary, therefore, to take unusual precautions in order to secure accurate observations, and to give each one its full weight.
The range of H 1255 is only four tenths of a magnitude, and on account of its brightness it is difficult to observe on all plates except those taken with the 1-inch Cooke lens. Henrietta Swan Leavitt
The range of H 1255 is only four tenths of a magnitude, and on account of its brightness it is difficult to observe on all plates except those taken with the 1-inch Cooke lens.
Periods of nine variables in this region, which are of the Algol type or closely resemble it, have been determined and are here discussed. Henrietta Swan Leavitt
Periods of nine variables in this region, which are of the Algol type or closely resemble it, have been determined and are here discussed.
Apparently no sharp dividing line can be drawn between true Algol stars and those whose variations are continuous. Henrietta Swan Leavitt
Apparently no sharp dividing line can be drawn between true Algol stars and those whose variations are continuous.
The number of these is so large that the publication of full results for all must be greatly delayed. Henrietta Swan Leavitt
The number of these is so large that the publication of full results for all must be greatly delayed.
When new lists of variables are published, therefore, it should be remembered that their discovery does not interfere materially with the study of individual objects. Henrietta Swan Leavitt
When new lists of variables are published, therefore, it should be remembered that their discovery does not interfere materially with the study of individual objects.
In the study of distribution now in progress here, the actual time devoted to the search for new variables is small, but thorough observation requires much time, while the discussion of results may be prolonged almost indefinitely. Henrietta Swan Leavitt
In the study of distribution now in progress here, the actual time devoted to the search for new variables is small, but thorough observation requires much time, while the discussion of results may be prolonged almost indefinitely.
The discovery of variable stars, at this Observatory and elsewhere, has progressed so rapidly during the last five years, that the difficulty of keeping pace in observing and discussing them has become very great. Henrietta Swan Leavitt
The discovery of variable stars, at this Observatory and elsewhere, has progressed so rapidly during the last five years, that the difficulty of keeping pace in observing and discussing them has become very great.