Where does this come from, and can I check it?

The dark cores sit at about 3,800 kelvin against a 5,800 kelvin surface. The figure is taken from NASA Science, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

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Sunspots look dark but are merely cooler

The dark cores sit at about 3,800 kelvin against a 5,800 kelvin surface A sunspot's umbra is roughly 1,500 to 2,000 kelvin cooler than the surrounding photosphere, so it emits less light and looks black by contrast. Strong magnetic fields choke off the churning convection that would otherwise carry heat to the surface. The surrounding penumbra shows fibrils of gas flowing inward and outward. It sits in Mondo's space collection, one of 200 facts that each trace back to the reference below.

Where this comes from

NASA Science

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Space & Astronomy trivia Science trivia

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Tags: sunspots, magnetism, sun

Sunspots look dark but are merely cooler: the short answers

Where does this come from, and can I check it?: The dark cores sit at about 3,800 kelvin against a 5,800 kelvin surface. The figure is taken from NASA Science, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a space fact?: Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.