Astronomy for the use of schools and academies (1882)
Gillet, J. A. (Joseph Anthony), 1837-1908, Rolfe, W. J. (William James), 1827-1910 · New York : Potter, Ainsworth, & Co. · leaf 213
phenomena were repeated, butin the inverse order. The penumbra on the inner edge ofthe spot narrowed much faster than that on the outer, dis-appeared entirely, and finally seemed to hide from sightmuch of the umbra nearly a whole day before the spotpassed from view around the limb. This is… … ASTRONOMY. !93 191. Sun-Spot Spectrum. —When the image of a sun-spotis thrown upon the slit of the spectroscope, the spectrum isseen to be crossed longitudinally by a continuous dark band,showing an increased general absorption in the region of thesun-spot. Many of the spectral lines are greatly…
Astronomy
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