Portal de Periódicos da CAPES

Summary of the Year's Work at Mount Wilson

1933; Institute of Physics; Volume: 45; Linguagem: Inglês

10.1086/124369

1538-3873

W. S. Adams,

History and Developments in Astronomy

It is a satisfaction to report that the exceptional progress in research recorded last year has shown no sign of abatement. Its future continuation, sufficiently assured by the productive vigor of the Observatory staff, will be further promoted by the establishment of close and effective cooperation with the California Institute of Technology, and by the initiation of promising new enterprises, some of which involve important additions to our instrumental equipment. In epitomizing the year's advances special mention should be made of Seares's researches on the masses of the stars, and on the progressive changes of temperature, diameter, and density that mark the course of stellar evolution ; the discovery by Stromberg of the identity of the two star streams found by Kapteyn among the A-type stars with the Taurus and the Ursa Major groups, and of the marked difference in stream motion of the giant and dwarfs of the later spectral types ; the development by Adams and Joy of a spectroscopic method of measuring the absolute magnitude (and hence the distances) of the white (A) stars, and its immediate application to 544 of these objects; the theoretical investigations of Russell on the nature of dark nebulae; the proof by Hubble that the radiation of the nebulae is stimulated by stars lying within them ; the discovery by Nicholson and Pettit that the total radiaion of certain red variables of the ninth magnitude is as great as that of white stars of the second magnitude ; the measurement by Abbot of the energy distribution in the spectra of certain of the brighter stars and the promise this work yields of great advances in this important field of investigation; the progress made by Michelson in the re-determination of the velocity of light and his contributions to other important physical problems ; the detection of invisible sun-spots by their Zeeman effect ; the import-