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:
“A good leg will fall, a straight back will stoop, a black beard will turn white, a fair face will wither, a full eye will wax hollow, but a good heart, Kate, is the sun and the moon—or rather the sun and not the moon, for it shines bright and never changes, but keeps his course truly.”
—William Shakespeare (1564–1616)
“O, for an engine, to keep back all clocks,
Or make the sun forget his motion!”
—Ben Jonson (c. 1572–1637)