credit: modification of work by NASA/Goddard
The sun would look as if we could see all of its parts from the center to the outer atmosphere.
The layers of the sun are different from one another, and each of them plays a role in generating the energy that the sun ultimately emits. We start with the core and work our way through the layers. The core of the sun is extremely dense and is the source of all its energy. Nuclear energy is released in the core. The core is about 20% the size of the sun’s interior & is thought to have a temperature of about 15 million K, making it the hottest part of the sun.
Above the core is a region known as the radiation zone, named for the main mode of energy transport it traverses. This area begins about 25% of the distance to the sun’s surface and extends up to about 70% of the way to the surface. The light generated in the core is transported very slowly through the radiation zone, because the high density of matter in this area means that a photon cannot travel too far without hitting a particle, causing it to change direction and lose some energy.
The convection zone is the outermost layer of the sun’s interior. It is a thick layer about 200,000 kilometers deep that transports energy from the edge of the radiation zone through huge convection cells, similar to a pot of boiling oatmeal. The plasma at the bottom of the convection zone is extremely hot & it bubbles to surface, where it gives off its heat to space. Once the plasma has cooled, it returns to the bottom of the convection zone.
Now that we have given a brief overview of the structure of the entire sun, in this section we will embark on a journey through the visible layers of the sun, starting with the photosphere, the visible surface.
