sunspot

Meanings

1. 1
   noun

   a temporary dark region on the Sun's photosphere that is cooler than its surroundings and has intense magnetic activity

   Astronomers tracked the sunspot as it moved across the visible face of the Sun.

A compound of sun + spot. Sunspots look dark by contrast with the hotter photosphere around them, and their number rises and falls through the roughly eleven-year solar cycle.

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