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:
“The prairies were dust. Day after day, summer after summer, the scorching winds blew the dust and the sun was brassy in a yellow sky. Crop after crop failed. Again and again the barren land must be mortgaged for taxes and food and next year’s seed. The agony of hope ended when there was not harvest and no more credit, no money to pay interest and taxes; the banker took the land. Then the bank failed.”
—Rose Wilder Lane (1886–1968)
“The sun was not so true unto the day
As he to me.”
—William Shakespeare (1564–1616)