sunspot(redirected from Penumbra (Sun))
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Any of the relatively cool dark spots appearing periodically in groups on the surface of the sun that are associated with strong magnetic fields.
1. (Astronomy) 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. (Pathology) Austral a small cancerous spot produced by overexposure to the sun
one of the relatively dark patches that appear periodically on the surface of the sun and affect terrestrial magnetism and certain other terrestrial phenomena.
Any of the relatively cool dark spots that appear in groups on the surface of the sun. Sunspots are associated with strong magnetic fields.
One of many relatively cool dark spots that appear periodically on the surface of the Sun.
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|Noun||1.||sunspot - a cooler darker spot appearing periodically on the sun's photosphere; associated with a strong magnetic field|