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

• sunspotted adjective
• sunspottedness noun

Etymology

Origin of sunspot

First recorded in 1805–15; sun + spot

Example Sentences

The Sun's magnetic cycle is a repeating pattern that lasts about 11 years, marked by fluctuations in sunspot numbers and a complete reversal of the Sun's magnetic poles.

From Science Daily

This means there are lots of sunspots on the surface which are like volcanoes and occasionally erupt.

From BBC

This means there are lots of sunspots on the surface which are a bit like volcanoes and occasionally erupt.

From BBC

During this maximum, the number of sunspots increases which leads to more Coronal Mass Ejections sending charged particles to Earth, creating the aurora.

From BBC

If you can elbow your way onto one of Majorca’s sunspots this summer, you will witness two unstoppable forces.

From BBC