Take a look up at a dark night sky, and you'll find it illuminated by hundreds or even thousands of individual twinkling points of light. While they might seem, to an untrained eye, to all be the same ...

The following is an excerpt from The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars, by Dava Sobel. The monumental work of stellar classification known as the ...

II. THE temperature relationships of the various groups in the classification of stars described in the previous article are further illustrated in a diagram which is reproduced in Fig. 6, from which ...

I. ALTHOUGH the observations made by Fraunhofer in 1814 first indicated that the spectra of stars were not all of the same character, it was the more systematic observations of Rutherfurd and Secchi ...