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
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.
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.
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.
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.
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.
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.
A straight line can readily be drawn among each of the two series of points corresponding to maxima and minima, thus showing that there is a simple relation between the brightness of the variables and their periods. Henrietta Swan Leavitt
A straight line can readily be drawn among each of the two series of points corresponding to maxima and minima, thus showing that there is a simple relation between the brightness of the variables and their periods.
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.
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.
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. Henrietta Swan Leavitt
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.
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.
