NASA SDO - AR1476, May 5 -6, 2012

Active Region 1476 has been one of the largest region since the 2003 "Halloween Storm". This video shows the path and development of this sunspot group from May 5 through May 11, 2012.

The Sun rotates on its axis once in about 27 days. This rotation was first detected by observing the motion of sunspots. The Sun's rotation axis is tilted by about 7.25 degrees from the axis of the Earth's orbit so we see more of the Sun's north pole in September of each year and more of its south pole in March.

Since the Sun is a ball of gas, it does not have to rotate rigidly like the solid planets and moons do. In fact, the Sun's equatorial regions rotate faster (taking only about 24 days) than the polar regions (which rotate once in more than 30 days). The source of this "differential rotation" is an area of current research in solar astronomy.

Credit: NASA SDO

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