The Sun

absorption angle Ångström appear atmosphere average beam bolometer bright lines calcium calories per square carbon cent Chapter chemical elements chromosphere clouds computed corona curve dark lines density diameter displacement earth earth's atmosphere eclipse effect elements emission energy faculæ flash spectrum Fraunhofer lines gaseous gases glass heat helium Hence hydrogen hydrogen lines indicate intensity latitudes less light line of sight mass maximum mean measured miles mirror motion Mount Whitney Mount Wilson nearly nebula Observatory observed orbit parallax perfect radiator period photographic photosphere plants plate pressure produce prominences radius rays regions reversing layer rotation Rowland's shown slit solar constant solar radiation solar rotation solar spectrum solar system spec spectra spectral types spectroheliograph spectroscope spectrum lines spots square centimeter stars stellar sun-spot sun's disk sun's limb surface telescope temperature tion trum velocity violet wave lengths zenith distance