The Sun
The Sun's photosphere has a temperature between 4500 and 6000 K (with an effective temperature of 5777 K) and a density of about 2×10−4 kg/m3; other stars may have hotter or cooler photospheres. The Sun's photosphere is composed of convection cells called granules—cells of gas each approximately 1000 kilometers in diameter with hot rising gas in the center and cooler gas falling in the narrow spaces between them. Each granule has a lifespan of only about eight minutes, resulting in a continually shifting "boiling" pattern. Grouping the typical granules are super granules up to 30,000 kilometers in diameter with lifespans of up to 24 hours. These details are too fine to see on other stars.
Read more about this topic: Photosphere
Famous quotes containing the word sun:
“These modern ingenious sciences and arts do not affect me as those more venerable arts of hunting and fishing, and even of husbandry in its primitive and simple form; as ancient and honorable trades as the sun and moon and winds pursue, coeval with the faculties of man, and invented when these were invented. We do not know their John Gutenberg, or Richard Arkwright, though the poets would fain make them to have been gradually learned and taught.”
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