Re: ATM site claims Sun's surface is solid
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Originally Posted by Van Rijn
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Originally Posted by Michael Mozina
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The sun glows because of the blackbody temperature at the surface. Sunspots glow too at a somewhat lower temperature. They are darker but they are far from dark.
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Huh? They are VERY dark to the naked eye. |
Probably because you destroyed your retina. Seriously, this is basic astronomy. You can't look at the sun with the naked eye for more than an instant without damaging the eye and you certainly can't identify sunspots that way. You have to use a filter or other method to reduce the intensity of the light. Sunspots only appear dark through a filter because they are relatively darker than the rest of the surface. From:
http://en.wikipedia.org/wiki/Sunspot
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A sunspot is a region on the Sun's surface (photosphere) that is marked by a lower temperature than its surroundings, and intense magnetic activity. Although they are blindingly bright, at temperatures of roughly 5000 K, the contrast with the surrounding material at some 6000 K leaves them clearly visible as dark spots. Interestingly, if they were isolated from the surrounding photosphere they would be brighter than an electric arc.
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That was pretty revealing re sunspot "darkness". If memory serves the apparent magnitude of a typical sunspot is about -14.5 to -15. A sunspot, if moved 180° from the Sun, would be the brightest object in the night sky.
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