Granule (solar physics)

When granulation is in astronomy, the granular structure of stellar surfaces referred to, especially the sun, because it is as close as a single star that its surface can be observed in detail. Here, the granulation is the fact that the surface appears divided into many small " grains " with dark boundary edges. These are referred to as granules. The individual granules have dimensions of up to 1000 km in diameter and exist for a few minutes.

The granulation is caused by convection in one of the visible " surface " of the photosphere, lower-level layer. This hot and so bright luminous material rises from the interior of the star to the surface, where it cools and sinks at the edge of a stream such as a darker material back. The difference in temperature is 500 K. Thus, the granulation is in contrast to the magnetic sunspot a purely thermal phenomenon.