His main contributions was in the study of solar and stellar spectra.
Calhoun checked the solar spectrum as a matter of course.
We have analyzed the solar spectrum over the past six months.
From 1861 onwards he paid special attention to the solar spectrum.
Consequently, its spectrum is the same as the solar spectrum.
When the two colors chosen match the solar spectrum that shows the greatest magnitude.
He discovers and maps hundreds of fine dark lines crossing the solar spectrum.
It is just not correct that the sun provides heat only from its infrared portion of the solar spectrum.
Parts of the Balmer series can be seen in the solar spectrum.
Yellow occurs between green and orange in the solar spectrum.