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.

sunspot

/ 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

sunspot

/ 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 .

Derived Forms

• ˈsunˌspotted, adjective

Other Words From

• sunspotted adjective
• sunspotted·ness noun

Word History and Origins

Origin of sunspot¹

First recorded in 1805–15; sun + spot

Example Sentences

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

From BBC

The sun's surface is a brilliant display of sunspots and flares driven by the solar magnetic field, which is internally generated through a process called dynamo action.

From Science Daily

Galileo was among the first astronomers to turn a telescope skyward and study sunspots, back in the early 1600s.

From Seattle Times

“Broadly speaking, though, we do know that activity and sunspot numbers should increase in this part of the cycle,” Tom Morgan, a meteorologist for the Met Office, said.

From New York Times

The periodic changes may be due to giant sunspots rotating in and out of view.

From Science Daily