Yes, the sun too rotates about its axis. But unlike the earth, which has rotation period of one day, the sun has a ‘differential rotation’.
That is, all parts of the sun do not have the same period of rotation. The period of rotation near its equator is 26.9 days, at sun spot zone (16 degrees north) it is 27.3 days and at the ole it is 31.1 days (syndical).
The sun’s enormous core temperature of 15 million degree Kelvin and a surface temperature of 6,000 degree Kelvin leave all its constituents in a high pressure, gaseous state called plasma. For the purpose of certain calculations, the top and the bottom ends of the visible sphere of the sun are designated as north and south poles respectively.
Photographs are taken daily and the movements of the spots, filaments and plages are observed for various latitudes and longitudes, for a long period of time. From this, the sidereal rotation period is calculated. The reason behind this phenomenon is still a puzzle to solar physicists.
