Search results
- Dictionarypenumbra/pɪˈnʌmbrə/
noun
- 1. the partially shaded outer region of the shadow cast by an opaque object.
- 2. a peripheral or indeterminate area or group: "an immense penumbra of theory surrounds any observation"
Powered by Oxford Dictionaries
1. a. : a space of partial illumination (as in an eclipse) between the perfect shadow on all sides and the full light. b. : a shaded region surrounding the dark central portion of a sunspot. 2. : a surrounding or adjoining region in which something exists in a lesser degree : fringe.
The penumbra (from the Latin paene "almost, nearly" and umbra "shadow") is the region in which only a portion of the light source is obscured by the occluding body. An observer in the penumbra experiences a partial eclipse.
PENUMBRA definition: 1. a part of a shadow in which only some of the light is blocked, used especially about a shadow…. Learn more.
The penumbra is a half-shadow that occurs when a light source is only partly covered by an object—for example, when the Moon obscures part of the Sun's disk. The other 2 areas are: Umbra – the shadow's dark center portion. Antumbra – the lighter part of the shadow that begins where the umbra tapers to a point. Why are there 3 shadows?
physics specialized us / pɪˈnʌm.brə / uk / pɪˈnʌm.brə /. Add to word list. a part of a shadow in which only some of the light is blocked, used especially about a shadow made during an eclipse: In a lunar eclipse, the outer shadow or penumbra is a zone where Earth blocks a portion of the sun's rays.
The partially shaded region around the shadow of an opaque body, when the light source is larger than a point source and only part of its light is cut off (contrasted with the full shadow or umbra); (esp. in Astronomy) that of the shadow cast by the moon on the earth in a solar eclipse, or by the earth on the moon in a lunar eclipse, resulting i...
Definition of penumbra noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
In a lunar eclipse, the edge of the earth's shadow — the part that isn't fully dark — is its penumbra. Sun spots also have a penumbra, the outer edge that's not quite as dark as the center. The word comes from the Latin root umbra, which means "shadow." The pen part means "almost," so a penumbra is "almost shadow."
1. the partly lighted area surrounding the complete shadow (umbra) of a body, as the moon, during an eclipse. 2. the less dark region surrounding the dark central area of a sunspot. 3. a vague, indefinite, or borderline area. Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by Houghton Mifflin Harcourt. All rights reserved.
1. a. the partial or imperfect shadow outside the complete shadow of an opaque body, as a planet, where the light from the source of illumination is only partly cut off. b. the grayish marginal portion of a sunspot. 2. a shadowy, indefinite, or marginal area.
