- one of the relatively dark patches that appear periodically on the surface of the sun and affect terrestrial magnetism and certain other terrestrial phenomena.
Origin of sunspot
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for sunspots
That seems to be what happens on a large scale when sunspots are numerous.
As to the number of sunspots, there is little evidence previous to about 1750.
The result of the comparison of earthquakes and sunspots is shown in Table 7.
The official explanation, issued by the stations themselves, was sunspots.Earth Alert!
In Wympland you get all the advantages of the sun and none of the drawbacks,—no sunblinds or sunstrokes or sunspots!The Other Side of the Sun
- 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
- informal a sunny holiday resort
- Australian a small cancerous spot produced by overexposure to the sun
Word Origin and History for sunspots
Online Etymology Dictionary, © 2010 Douglas Harper
- 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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.