Granulation
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Short-term evolution of solar granulation
Swedish 1-m Solar Telescope
The solar photosphere is characterized by the presence of an ever-lasting granulation pattern which is due to convective motions of the gas on the solar surface. Convection is a very efficient way to transport heat from the subsurface layers, which are hot, to the surface, which is cooler. Bright granules are convective cells where hot gas rises in the atmosphere and releases its heat before sinking back to the surface through the darker lanes at their borders (the so-called intergranular lanes).
Granules on the solar surface occur in a variety of sizes and shapes. Their average diameter is on the order of 1500-2000 km. They are very dynamic, with lifetimes of 5 to 10 minutes.
The movie shows the evolution of the solar granulation in the quiet Sun at disk center, as observed with a wideband filter at 436.4 nm at the Swedish 1m Solar Telescope. The duration of the observations was 27 minutes. One can clearly see the highly changing granulation pattern, with granules and intergranular lanes lasting a few minutes only. Also apparent are tiny bright points located in intergranular lanes. These are relatively intense magnetic elements that interact with the convective motions of the solar surface and also between them.
To download the movie, click HERE
Movie credit: Michiel van Noort and Luc Rouppe van der Voort (ITA, University of Oslo)
Text credit: Luis Bellot Rubio (IAA-CSIC)
Source: SST Galleries