penumbra

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(1) The lighter, outer shadow of a double-shadow effect produced by a large, unfocused source of light shining on an interfering opaque object. A penumbral eclipse is one in which the eclipsed object passes through the penumbral shadow. (2) The lighter area, marked by radial filaments, that may surround the darker, central umbra of a sunspot. Penumbral waves are waves observed in the light of H-alpha that move out from the center of a sunspot across the penumbra.

noun

Comparative darkness that results from the blocking of light rays: shade, shadow, umbra, umbrage. See light/darkness.

A blurred edge to an image, a halo effect, in an x-ray film caused usually by an overlarge focal spot exacerbated by a long object-to-film distance.

For a list of words related to penumbra, see:

• Optics - penumbra: partially illuminated portion of a shadow
• Celestial Phenomena and Points - penumbra: partly lighted area that surrounds complete shadow of celestial body during eclipse

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See words rhyming with "penumbrae."

Dansk (Danish)
n. - halvskygge

Nederlands (Dutch)
halfschaduw, donker gebied rondom zonnevlek, periferie, vaag/ onduidelijk gebied, rechten impliciet in grondwet

Français (French)
n. - (Astron) pénombre (littér)

Deutsch (German)
n. - Halbschatten

Ελληνική (Greek)
n. - σκιόφως

Italiano (Italian)
penombra

Português (Portuguese)
n. - penumbra (f)

Русский (Russian)
полутень

Español (Spanish)
n. - penumbra

Svenska (Swedish)
n. - halvskugga

中文（简体）(Chinese (Simplified))
半影

中文（繁體）(Chinese (Traditional))
n. - 半影

한국어 (Korean)
n. - 반영, 명암 농담의 경계 부분, 어두운 그림자

日本語 (Japanese)
n. - 半影, 明暗の境目

العربيه (Arabic)
‏(الاسم) شبه ظل, ظليل‏

עברית (Hebrew)
n. - ‮צל אפור וחיוור העוטר לפעמים את הצל השחור המלא, פלג-צל‬

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