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:
““What,” it will be questioned, “When the sun rises, do you not see a round disc of fire somewhat like a guinea?” O no, no, I see an innumerable company of the heavenly host crying “Holy, Holy, Holy is the Lord God Almighty.””
—William Blake (1757–1827)
“Oh, what a catastrophe for man when he cut himself off from the rhythm of the year, from his unison with the sun and the earth. Oh, what a catastrophe, what a maiming of love when it was a personal, merely personal feeling, taken away from the rising and the setting of the sun, and cut off from the magic connection of the solstice and the equinox!”
—D.H. (David Herbert)