Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. Our Sun itself frequently has sunspots , relatively cool dark magnetic depressions that move across its surface. The vertical bar on the right gives a temperature scale in kelvins . This giant, binary, RS CVn star , also known as XX Trianguli , is visible with binoculars in the constellation of Triangulum . The starspot is thought to be caused by large magnetic fields that inhibit hot matter from flowing to the surface.
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