Article

Heavenly Heat

May 1941
Article
Heavenly Heat
May 1941

The latest result of the firmamentgazing of Dr. Walter S. Adams '98, director of the Mount Wilson Observatory of the Carnegie Institution, is reported to be the evidence he has found that the atmospheres of the biggest stars are boiling merrily.

Using a Coude spectrograph, the largest yet devised for stellar studies, attached to the 100-inch telescope and exposing the photographs for five to six hours each, Dr. Wilson pinned down some of the big fellows, including Antares, estimated to be 385 times as large as the sun, and Ras Algethi, 800 times as large as the sun. The iron, titanium and chromium bands in the spectra of these red giants showed up as double, while in other stars only one band of each could be observed. This was interpreted to mean that the stars' atmospheres were in violent motion, part of the atmosphere rising, the other falling, with a difference in velocity of about twelve miles a second.

These torrid spheres are described as cool, however, as stars go, running about 5,000 degrees fahrenheit, or one-half the temperature of the sun.