sunspot

American  

[suhn-spot] / ˈsʌnˌspɒt /

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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sunspot British  

/ ˈsʌnˌspɒt /

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. a small cancerous spot produced by overexposure to the sun

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sunspot Scientific  

/ sŭn′spŏt′ /

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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Other Word Forms

Derived Forms

• sunspottedness
  noun
• sunspotted
  adjective

Etymology

Origin of sunspot

First recorded in 1805–15; sun + spot

Example Sentences

In September 2023, a new covered market and business centre - Sunspot - was opened at the coastal village.

From BBC • Oct. 30, 2025

Canto starred alongside Berry as Sunspot, a solar energy manipulating mutant, in the 2014 film.

From Los Angeles Times • Jan. 10, 2024

The mountaintop observatory in Sunspot closed for 11 days in 2018, but the research association that manages it has said only that an unspecified security issue was the reason for the closure.

From Washington Times • Aug. 8, 2020

Sunspot activity waxes and wanes, oscillating over an 11 year period.

From New York Times • Feb. 25, 2020

Sunspot activity continues at a high level and is steadily mounting in violence.

From Disturbing Sun by Richardson, Robert S. (Robert Shirley)