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The Hertzsprung-Russell diagrams of old stellar Populations

Published online by Cambridge University Press:  14 August 2015

W. A. Baum*
Affiliation:
Mount Wilson and Palomar Observatories

Extract

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The color-magnitude diagrams of globular star clusters are described and attention is called to some evolutionary implications. The predominant stellar population of large elliptical galaxies is shown to be unlike that of globular star clusters but probably similar to that of the older stars in the disk of our Galaxy. The same is true of the population in the nuclei of spiral galaxies. Dwarf ellipticals, on the other hand, are found to have a globular-cluster-type population. The kind of stellar population predominant in a galaxy seems to depend upon the magnitude and the rotational flattening of the galaxy. A unified evolutionary hypothesis is proposed to account for the existence of galaxies of different types.

Type
I. The Observational Data on the Hertzsprung-Russell Diagram
Copyright
Copyright © CNRS 1959 

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