one of the relatively dark patches that appear periodically on the surface of the sun and affect terrestrial magnetism and certain other terrestrial phenomena.
- sunspotted, adjective
- sun·spot·ted·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use sunspot in a sentence
His successors later noticed that sunspots often produce bursts of radiation called solar flares.Solar storms can wreak havoc. We need better space weather forecasts | Ramin Skibba | February 26, 2021 | Science News
This week, the first image of a sunspot from the high-definition Inouye telescope was finally published.
To capture the sunspot, the researchers pointed the telescope’s 13-foot mirror—three times wider than any other solar telescope—towards the central area of the star.
This recent sunspot image was captured on January 28 of this year, and it’s just one part of a bigger series.
The largest solar telescope on Earth has gotten the sharpest glimpse ever of a sunspot.This new image reveals a sunspot in unrivaled detail | Christopher Crockett | December 11, 2020 | Science News
And Bishop, Colossus, Warpath, Blink, sunspot, Quiksilver, Stryker and Havoc will all be there too.
For even this great sunspot was but small as compared with the Sun as a whole.The Science of the Stars | E. Walter Maunder
They would not be strictly accurate, because a sunspot could knock all meaning out of any reading beyond two decimal places.Pariah Planet | Murray Leinster
The sunspot cycle has appeared to average 11.2 years in length, and has been called the 11-year cycle.Climatic Changes | Ellsworth Huntington
That is, you cannot connect a particular sunspot group with a particular S-Region.Disturbing Sun | Robert Shirley Richardson
It means you can only approximately predict the future course of sunspot activity.Disturbing Sun | Robert Shirley Richardson
British Dictionary definitions for sunspot
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
- sunspotted, 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
Scientific definitions for sunspot
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.