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sunspot

[suhn-spot]
noun
  1. one of the relatively dark patches that appear periodically on the surface of the sun and affect terrestrial magnetism and certain other terrestrial phenomena.
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Origin of sunspot

First recorded in 1805–15; sun + spot
Related formssun·spot·ted, adjectivesun·spot·ted·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for sunspots

Historical Examples

  • That seems to be what happens on a large scale when sunspots are numerous.

    Climatic Changes

    Ellsworth Huntington

  • As to the number of sunspots, there is little evidence previous to about 1750.

    Climatic Changes

    Ellsworth Huntington

  • The result of the comparison of earthquakes and sunspots is shown in Table 7.

    Climatic Changes

    Ellsworth Huntington

  • The official explanation, issued by the stations themselves, was sunspots.

    Earth Alert!

    Kris Neville

  • In Wympland you get all the advantages of the sun and none of the drawbacks,—no sunblinds or sunstrokes or sunspots!


British Dictionary definitions for sunspots

sunspot

noun
  1. any of the dark cool patches, with a diameter of up to several thousand kilometres, that appear on the surface of the sun and last about a week. They occur in approximately 11-year cycles and possess a strong magnetic field
  2. informal a sunny holiday resort
  3. Australian a small cancerous spot produced by overexposure to the sun
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Derived Formssunspotted, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for sunspots

sunspot

n.

1868, in astronomy, from sun (n.) + spot (n.). Earlier "a spot on the skin caused by exposure to the sun" (1818).

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Online Etymology Dictionary, © 2010 Douglas Harper

sunspots in Science

sunspot

[sŭnspŏt′]
  1. Any of the dark, irregular spots that usually appear in groups on the surface of the Sun (its photosphere), lasting from a few days to several weeks or more. Sunspots appear dark because they are cooler, by up to 1,500°K, than the surrounding photosphere. They are associated with strong magnetic fields and solar magnetic storms moving in a vortex pattern, similar to a tornado on Earth. The number of sunspots waxes and wanes over an 11-year period; at maximum activity there are often increased numbers of solar flares.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

sunspots in Culture

sunspots

Dark spots on the surface of the sun caused by magnetic storms.

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Note

The number of sunspots goes through a maximum and minimum about every eleven years. During periods of maximum sunspots, the elementary particles associated with the spots cause disturbances in the atmosphere of the Earth and interfere with radio and television communication.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.