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umbra |
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umbra: see eclipse eclipse [Gr.,=failing], in astronomy, partial or total obscuring of one celestial body by the shadow of another. Best known are the lunar eclipses, which occur when the earth blocks the sun's light from the moon, and solar eclipses, occurring when the moon blocks the
..... Click the link for more information. ; sunspots sunspots, dark, usually irregularly shaped spots on the sun's surface that are actually solar magnetic storms. The Chinese recorded dark features on the sun seen with the naked eye in 28 B.C. ..... Click the link for more information. . umbra 1. a region of complete shadow resulting from the total obstruction of light by an opaque object, esp the shadow cast by the moon onto the earth during a solar eclipse 2. the darker inner region of a sunspot umbra [′əm·brə] (astronomy) The dark, central region of a sunspot. (optics) That portion of a shadow which is screened from light rays emanating from any part of an extended source. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
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