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 related to the sun:
“For myself I found that the occupation of a day-laborer was the most independent of any, especially as it required only thirty or forty days in a year to support one. The laborer’s day ends with the going down of the sun, and he is then free to devote himself to his chosen pursuit, independent of his labor; but his employer, who speculates from month to month, has no respite from one end of the year to the other.”
—Henry David Thoreau (1817–1862)