Today's movie attempts to follow a fixed location on the sun as it comes back around after each rotation period. Each frame advances time by one Carrington rotation period, around 27.3 days. Following one spot on the sun is a tricky endeavor because the sun is not a solid body and is therefore subject to differential rotation, meaning that different latitudes have different rotation rates. The polar regions of the sun rotate fully about once every 34 days, while material at the equator takes only about 25 days. Richard Carrington used low latitude sunspots to determine the rotation period of the sun and came up with a sidereal period of 25.38 days, which, because the Earth is orbiting the Sun, appears to us as 27.28 days. In this movie, several active regions can be observed to appear, linger for a rotation or two, and then dissipate. But this perspective is perhaps even more interesting for illuminating the dynamic nature of coronal holes, the dark regions of cooler and lower-density plasma, which can be seen here morphing and migrating throughout the corona.

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