Umbra and Penumbra - Hutchinson encyclopedia article about Umbra and Penumbra Printer Friendly
Dictionary, Encyclopedia and Thesaurus - The Free Dictionary
3,581,293,471 visitors served.
forum Join the Word of the Day Mailing List For webmasters
?
Dictionary/
thesaurus
Medical
dictionary
Legal
dictionary
Financial
dictionary
Acronyms
 
Idioms
Encyclopedia
Wikipedia
encyclopedia
?

umbra
(redirected from Umbra and Penumbra)

    Also found in: Dictionary/thesaurus, Medical, Encyclopedia, Wikipedia 0.01 sec.

umbra

Enlarge picture
Shadows are created as light travels in straight lines and so cannot bend around objects, and is therefore blocked.

Central region of a shadow that is totally dark because no light reaches it, and from which no part of the light source can be seen (compare penumbra). In astronomy, it is a region of the Earth from which a complete eclipse of the Sun can be seen.
How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content.
?Page tools
Printer friendly
Cite / link 		Feedback
?Sign in SSL protected
Email:
Password:
Register

Mentioned in?  References in periodicals archive?   Hutchinson browser?   Full browser?
 
The researchers conclude that there is a unified physical explanation for the structure of sunspots in umbra and penumbra that's the consequence of convection in a magnetic field with varying properties.
Virtual model of sunspots may unlock Sun's mysteries by Asian News International
 
 
 
Hutchinson Encyclopedia
?

Terms of Use | Privacy policy | Feedback | Copyright © 2012 Farlex, Inc.
Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.